Encounter Bubbles

June 6th, 2004

Czechy doubt: Encounter Bubbles.

Your PDA: A Wireless Web and Music Server

June 4th, 2004

Imagine sharing the collection of MP3 music files that you listen to on your PDA wirelessly with anyone nearby. Imagine converting that PDA into your own mobile, wireless Web server, through which anyone nearby who has a wi-fi enabled laptop or device can browse and download whatever Web pages, photos or other content that you choose to offer up.

A new application called Pocket Rendezvous allows you to do that. This is exciting because it takes the mobile personal Web server paradigm (as seen in Intel’s Personal Servers and in Julian Bleecker’s Wi-fi Bedouin project), and rolls it out in a form that will run on mobile devices that thousands of people already use.

But get this: while Pocket Rendezvous uses the device discovery and networking protocol most famous for its use in Apple’s Rendezvous system, Pocket Rendezvous runs only on (Microsoft) PocketPC devices! How darkly ironic… Nonetheless, bravo to Simeda, the small German software firm behind Pocket Rendezvous. I hope they port this to PalmOS soon so I can use it on my wi-fi enabled Palm.

(Thanks to Joe, Howard and The Register for the tip.)

Bedouin Devilry

March 22nd, 2004

Julian Bleecker’s wifi.Bedouin project has my mind churning. Bleecker frames this as a product and a service: essentially it’s a laptop in a backpack with wi-fi antennas, a PDA remote control, and software that creates your own little “island Internet.”

Forget about the packaging. The big innovation here lies in the paradigm, in viewing your wi-fi-enabled laptop as a server and a filter rather than a client.

What can you do with this? Here’s an example: have fun in Starbucks. Walk into a Starbucks cafe, sit back and watch customers come in, fire up their laptops and connect to your wi-fi node. They think they’ve jacked in to the Internet, but really they’re connected to your mobile server. You can serve their Web browsers whatever content you want — an art piece, brand-damaging fake Starbucks ads, fake coupons, photos of your cat, whatever. Mix your content with real Internet connectivity and content served up via the cafe’s wi-fi service. (Combine this with a Guerilla Cafe DJ setup and you’ve got a toolkit that would make Starbucks interventionist Reverend Billy proud.)

It’s important that we engage in this sort of play and think through these things, because not all the possibilities brought to light here are funny. McDonald’s or Starbuck’s or anyone else can intercept passwords and can easily monitor, record, forge and censor unprotected wi-fi communications. We can prevent such misdeeds through technical means, but before the solutions can be perfected and adopted we need to raise public awareness that the problems exist. Pranksters can spread this sort of consciousness.

This is just one example of what we can do with systems like Bedouin. Check out Bleecker’s scenarios page (and click through the three scenarios) for more.

3/24/04 UPDATE: Arthur Law brings up two other fun possibilities. (1) For business people and software developers: why not put the project work on a bedouin server and huddle the workgroup around a campfire? (2) For video game afficionados: won’t weddings and funerals be more fun when you and your laptop-toting friends engage in action-packed shoot-em-up tournaments during the ceremonies? Why wait for high-speed Internet coverage to reach your destination when you can bring the connectivity with you?

5/04/04 UPDATE: I recently came across another intriguing application that converts local machines (in this case, handheld computers) into miniature wi-fi Web servers. It’s called Hocman and it’s designed to allow motorcyclists to exchange social information via HTTP when they encounter one another on the road. Details here.)

5/16/04 UPDATE: It turns out that Intel Research has been doing its own work using the mobile server paradigm, using tiny Personal Servers.

I Want My Wi-Fi Telephony

January 4th, 2004

Last February I requested a small, cheap mobile device that:

  • notifies me when I’m within range of an open wi-fi (wireless Internet) access point, and:
  • allows me to call any telephone number on the planet, nearly free of charge, whenever I’m within range of a Wi-Fi signal, via a simple numeric-keypad interface.

    Back then, the hardware necessary to make this a practical reality wasn’t cheap and it wasn’t widely in use. Now it is. Many of the most popular PDAs (personal digital assistants), like my new Palm Tungsten C, provide Web browsers and high-bandwidth wi-fi Internet connectivity.

    We have the hardware. We have the infrastructure — the cities are becoming saturated with wi-fi hotspots, many of them free for public use, and robust Internet telephony networks have been in use for years.

    And we have the client software — but it hasn’t been designed for the right devices. A handful of firms like Dialpad and Net2Phone already provide cheap PC-to-phone voice service. But none of them seem to have ported their client applications for use on PDAs.

    What are these firms waiting for? For a very modest investment in resources, Dialpad and its competitors can make a very compelling offer: global telephone service on the go for prices less than one-tenth what you pay for mobile or even land-line phone service.

    Dialpad: I have my portable wi-fi telephone and I’m ready to pay you to use it. What are you waiting for?

  • Free Berkeley Wi-Fi Cafes

    September 7th, 2003

    Below I’ve posted a map and a list of cafes near the University of California, Berkeley campus that offer free wireless Internet access. If you have a laptop or other device with a Wi-Fi (802.11b) card, turn it on in one of these places to enjoy a free high-speed connection.

    I’m surprised that so few free wi-fi cafes exist in Berkeley, considering that more than 70 such cafes thrive in San Francisco. Do you know of any free wi-fi cafes near the UC Berkeley campus that I’m missing? If so, please let me know: sean[at]

    Help expand this list: next time you pass one of those big cafes near campus that charge exorbitant usage fees, go in and tell the manager that she’s losing business to the dozens of Bay Area cafes that provide free wi-fi access.

    UPDATE 6/26/05: If you use Windows and you’re interested in seeing who’s in cafes and at other hotspots nearby, check out Meetro. It’s not available for Macs so I haven’t been able to try it out but it looks like fun. -Sean
    Read the rest of this entry »

    One Conference, Two Worlds

    April 27th, 2003

    laptops.jpgThis week’s O’Reilly Emerging Technology Conference in Santa Clara, California was great fun. I enjoyed the presentations and the ideas, but it was the behavior of the attendees that really fascinated me.

    The conference wasn’t all “there.”

    Much of it took place elsewhere, and everywhere — in cyberspace. My attention was always torn between the physical conference and the virtual conference.

    I’ve never seen so many networked gadgets in use simultaneously in one place. During any given session, much of the audience had their laptops open and online thanks to power outlets and wireless Internet service throughout the conference rooms, lounges and hallways. I was immersed in bandwidth; I was surrounded by a chorus of whirring laptops and clicking keys.

    For me, this was a totally new sort of event — but soon, experiences like this will become commonplace.

    The typical scene: up front the speaker presents her talk, projecting a slide show or a demo onto the wall-sized screens. A glance around the darkened room reveals dozens of ghostly blue-white faces gazing into laptop screens.

    confab.gifMany of them are engaged in online chat rooms. ConFab, a Web-based chat tool, was built just for the conference. It allows a person to mouse-over a map of the conference rooms, to specify which physical-world room he’s sitting in, to engage in text chats with other attendees, and to see how many people are logged into each conference room. He can even pay a virtual visit to another conference room to find out what people are chatting about over there.

    (Network problems made staying connected to ConFab very difficult. But people conferred in more traditional Internet Relay Chat rooms too.)

    In the chat rooms people crack jokes and trade opinions about what the speaker is saying, and they write brief summaries of what’s going on for people who are tuned in to the conference from other parts of the planet.

    People read other folks’ comments. They examine the speaker’s Web site. They tune in to chats going on simultaneously in the other conference sessions, judging whether to step out and join the session going on next door.

    And they blog. I watched at least three people pull out digital cameras during presentations, take snapshots and upload the images to their blogs right there.

    laptops2.jpgPeople collaborate to take notes on the presentations and discussions using wikis. Groups of people use Hydra, a collaborative editing tool that allows multiple users to elegantly write, edit and add to a single document simultaneously.

    That pattern was repeated endlessly throughout the conference. Everyone’s energies were divided between cyberspace and the physical world. This is a fascinating phenomenon, but when the novelty wears off will such connectedness make for better or worse conferences?

    Did the average attendee go home with more or less knowledge, with more or fewer useful acquaintances, with more or less encouragement than they would have acquired without the digital networking? What do you think?

    The conference left me more confused about these questions than ever. For one thing, I wasted a lot of my attention and energy dealing with a couple of basic technical problems that the organizers can easily iron out in time for next year’s conference. But next year, won’t my attention be devoted to a new set of problems to wrestle or configurations to fine-tune as more real-world subtleties slip by unnoticed?

    I want to experiment more with this, and I know I won’t have to wait long.

    (A freakish footnote: I’m writing this entry on my laptop in a Berkeley WiFi cafe, days after the conference ended. Three other geeks bend over three other laptops by the window. They’re talking about their experiences at the same conference, as they post entries to their own blogs about it. Should I laugh or cry?)

    (Photos in this entry by Derrick Story of the O’Reilly Network.)

    Free Wi-Fi Cafes in San Francisco

    March 3rd, 2003

    [Also see the cheesebikini map of free Berkeley wi-fi cafes]

    Here are a map and a list of San Francisco cafes that offer free wireless Internet access. If you have a laptop or other device with Wi-Fi (wireless Internet) capability, turn it on in one of these places to enjoy a free high-speed connection.

    San Francisco Wi-Fi Map - See Key Below

    UPDATE 3/2/05: A four-block zone of Chestnut Street in San Francisco’s �ber-gentrified Marina District is now immersed in free wi-fi, courtesy of AnchorFree. The wi-fi zone covers Chestnut between Fillmore and Scott Streets, according to MacWorld. Thanks to Denis Hiller for the tip — and the wi-fi!

    Why certain cafes disappeared from the list and map: In late 2003, ZRNet, a company that outfitted many cafes with wi-fi hot-spots, withdrew free wi-fi service from all of these cafes, so I removed ZRNet cafes from the list. These cafes include: Atlas Cafe (ouch!), Cole Valley Cafe, Cafe XO, Tart to Tart, Cafe International, Brainwash Cafe and Laundromat, the Muddy Waters cafes, most of the Royal Grounds cafes, Cafe La Taza, Java on Ocean, Java Beach and Simple Pleasures. – Sean, 11/7/03

    2 H Cafe: 380 17th Street, at Sanchez. Jason Harlan reports that now an employee here “forces you to share tables with other laptop users… and he’s rude.” map | site

    3 Jumpin’ Java Coffee House & Eats: 139 Noe, at 14th. map

    4 Maggie Mudd: OK, it’s an ice cream shop, not a cafe. But I think they serve coffee… I haven’t stepped inside this place; their Web site frightens me. 903 Cortland Ave. at Gates. map | site

    5 Maxfield’s House of Caffeine: Dolores at 17th. Matadors fought bulls nearby! Don’t take my word for it, ask about it in the Mission Dolores museum at San Francisco’s oldest church, two doors up on Dolores. Or check out the bullfight pictures here (the sixth and seventh illustrations from the bottom). But I digress… map
    6 Morning Due Cafe: 3698 17th Street, at Church Street. Thanks to Rick Ehrlinspiel for the tip. Added 12/31/03. map

    7 Caffe Puccini: (NOTE: Wi-Fi connection here is weak.) This cafe doesn’t provide Wi-Fi access, but they’re within range of someone’s open Wi-Fi hub. When sitting at the south side of the cafe — the side closest to Broadway — I can pick up a low- to medium-strength signal. Unfortunately I couldn’t find any power outlets. Not a perfect situation, but this is a cozy cafe that serves great strong coffee to tourists and classic North Beach characters. 411 Columbus Ave, between Green and Vallejo. map

    8 Rockin’ Java: 1821 Haight Street between Shrader and Stanyan, just East of Golden Gate Park. map

    9 Martha & Bros. Coffee on Church: (NOTE: Wi-Fi connection may not be strong.) This cafe doesn’t provide free Wi-Fi access, but they’re within range of someone’s open Wi-Fi hub. (This cafe does provide fee-based Wi-Fi access via Surf and Sip; select the “” signal for free access or select “SurfandSip” for the stronger fee-based signal.) Thanks to Brad Lauster for the tip. And big thanks to Cliff Skolnick for sharing his home access point with the public! 1551 Church Street, at Duncan. map | site

    10 Peet’s Coffee on Fillmore: (NOTE: Wi-Fi connection may not be strong.) Dave Holmes-Kinsella reports: “If I sit *outside* at Peet’s on Sacramento & Fillmore, there’s a varying number of free WiFi A/Ps available.” 2197 Fillmore Street, at Sacramento. map

    11 Oakside Cafe: (NOTE: This cafe closes at 3 pm.) Thanks to Brian McCarthy for the tip. 1195 Oak Street, at Broderick. map

    12 Mario’s Bohemian Cigar Store Cafe: (NOTE: Free Wi-Fi connection may not be strong.) This cafe doesn’t provide free Wi-Fi access, but they’re within range of someone’s open Wi-Fi hub. It’s a cozy little North Beach cafe in a beautiful setting with good coffee and power outlets in back. (This cafe does provide fee-based Wi-Fi access via Surf and Sip; select the “thiebaud apple network” signal for free access or select “SurfandSip” for the stronger fee-based signal.) 566 Columbus Avenue, at Union, across the street from Washington Square Park. Added 3/28/03. map | site

    14 Internet Wired Cafe: In addition to regular WiFi (802.11b), this cafe offers one of the new, faster, 802.11g hotspots. Enjoy the free wi-fi, but brace yourself for the cheesiest policy in town: using a power outlet will cost you $1 per hour. By raising the cost of their coffee by ten cents per cup and cancelling this pathetically stingy rule, they’d make make more money and they’d stop insulting their customers. But hey, it’s a free country; let them keeping diverting business to the more than forty other free wi-fi cafes in town that respect their customers. Thanks to “toor” for the tip. 1392 9th Avenue, at Judah. Added 3/30/03. map | site

    15 Oh Java! Cafe: Thanks to Kevin for the tip. 562 Central Avenue, at Grove. Added 4/15/03. map

    16 Central Coffee, Tea & Spice: NOTE: The hot-spot here is WEP-encryped; you have to ask at the front counter for the passcode, which the owner changes regularly to “keep people honest.” This doesn’t really make sense, because any dishonest person could easily go to the front counter and copy down today’s passcode. But anyway, ask for the code and type it into your Wi-Fi card settings. This is kind of a hassle, but the coffee and the music were good when I visited the place. Thanks to Kevin for the tip. 1696 Hayes St. at Central Ave. Added 4/15/03. map

    17 Crepe Soleil: Thanks to Stew for the tip. Polk Street near Pine. Added 4/15/03. map

    18 Venture Frogs: This is not really a cafe, but cofounder Tony Hsieh says people are welcome to use their free wifi connection, and they serve coffee and tea. 1000 Van Ness, at O’Farrell. Added 4/15/03. map | site

    19 Castro Country Club: Thanks to “csmoll” for the tip. 4058 18th Street, at Castro. Added 4/19/03. map | site

    20 Caffe Roma: I love this cafe; thanks to Ben Hammersley for the tipping me off to their new wifi service. 526 Columbus, between Green and Union. Added 4/19/03. map | site

    21 Golden Gate Perk: Thanks to Chris Bucoy Brown for the tip. Bush at Kearny. Added 4/19/03. map | site

    24 Nani’s Cafe: Thanks to Eric L. and Natty for the tips. 2739 Geary Boulevard, between Masonic and Wood. Added 4/26/03. map | site

    25 Sacred Grounds: Thanks to Cameron for the tip. 2095 Hayes Street, at Cole. Added 4/26/03. map | site

    27 The Canvas Cafe/Gallery: Thanks to Adrian Elliot for the tip. 1200 9th Avenue at Lincoln Way, just south of Golden Gate Park. Added 4/26/03. map

    28 Dulcinea Cafe and Catering: This cafe doesn’t provide its own hotspot, but from there you can supposedly reach the hotspot next door at DNA Lounge. Thanks to DNA’s Jamie Zawinski for the tip — and for the bandwidth. 371 11th Street, between Harrison and Folsom. Added 4/26/03. map | site

    30 Cup a Joe: It’s “a great cafe with good light, couches upstairs, lots of plugs, and the best banana bread around,” according to Corii Liau. Thanks for the tip, Corii. 1901 Hayes Street, at Ashbury. Added 5/24/03. map

    33 Pearls International Beverages: Galen reports that Pearls offers free 802.11a and 802.11b Wi-Fi access. 329 West Portal Avenue, between 14th and 15th. Added 5/26/03. map

    34 JavaCat Cafe: 5549 Geary Blvd, between 19th and 20th. Added 5/26/03. map

    35 The Coffee Bean and Tea Leaf: 2201 Fillmore Street, at Sacramento. Thanks to praxis for the tip. Added 6/14/03. map | site
    36 Metro Crepe: 1 Sansome Street, at Market, in the courtyard. Thanks to des for the tip. Added 6/21/03. map

    37 Samovar Tea Lounge: 498 Sanchez Street, at 18th Street. At the site of the old Chat Cafe. Thanks to Robert James Sandler for the tip. Added 6/28/03. UPDATE 12/31/03: “Alec” and “Bobby O.” report intermittent wi-fi availability at Samovar; Bobby O. says this cafe turns off its hot spot on weekends and discourages use of neighboring hotspots within Samovar. map | site

    41 Skylight Caf�: 1720 Taraval Avenue, at 28th Avenue. Thanks to Victor d’Allant for the tip. Added 8/10/03. map

    43 Muddy’s Coffee House: 1304 Valencia Street, at 24th Street. Thanks to Romel for the tip. Added 9/9/03. map
    46 Sea Biscuit Coffee Shop : 3815 Noriega Street, at 45th Avenue. Thanks to Vernon Kuhns for the tip. Vernon says the place is “Small, homey, and good sound track.” Added 11/3/03. map
    47 Joey’s: 517 O’Farrell Street, at Jones Street. Thanks to John Abbe, who reports that this is “another laundromat/cafe, apparently with 802.11g,” and that they offer “‘Espresso, Ice Cream, Sausage’ (the sausage was okay, but nothing special)’ with outlets available. Added 11/3/03. map

    48 Cafe Francisco: 2161 Powell Street, at Francisco Street. Thanks to RacerX, who reports that two, sometimes three, open wi-fi access points from nearby homes are within range of this cafe. RacerX reports: “Coffee and tea are both cheaper than at Caffe Roma, and there is plenty of outside seating in the shade.” Added 11/3/03. map

    50 Puccini & Pinetta: 129 Ellis Street, at Cyril Magnin Street. Thanks to John Abbe for the tip. Added 11/3/03. map

    51 Westin St. Francis Hotel: 335 Powell Street, at Geary Street. Thanks to John Abbe, who reports: “Access is free, but you fill out a web form every 1/2 hour. There’s an outlet along the wall in the back right of the ground floor. The open snack/drink area there has some comfy seats, and expensive drinks/snacks. The connection is also available from a corridor on the second floor, but not the higher floors…” Added 11/3/03. map

    52 Caffe La Piazza: 700 Columbus Avenue at Filbert Street. Thanks to Vernon Kuhns for the tip. Vernon reports that this cafe “is next to an open 802.11b hub. It has available outlets, and, most importantly is under new management (a friend). Say Hi to Charley and Jing if you visit.” Added 11/3/03. map
    53 Cole Valley Cafe: 609 Cole Street, at Haight Street. Thanks to Jesse for the tip. Added 12/31/03.
    map | site
    –>54 Bean Bag Cafe: 601 Divisadero Street, at Hayes Street. Thanks to Rick Ehrlinspiel for the tip. Added 12/31/03. map

    55 Bahia Cafe: 1901 Ocean Avenue, at Ashton Avenue. Thanks to Alan for the tip. Added 12/31/03. map

    56 Cafe Evolution: 1336 9th Avenue, between Irving and Judah. Thanks to toor for the tip. Added 10/21/04. map | site

    57 Cup A Joe: 896 Sutter Street, at Jones Street. Thanks to eamonn for the tip. Added 10/24/04. map

    58 Cafe Murano: 1777 Steiner Street, at Sutter. Added 10/24/04. map

    59 Cafe Medjool: 2516 Mission Street, at 21st Street. Thanks to Cheu for the tip. Added 10/24/04. map

    60 Kaleo Cafe: 1340 Irving Street , at 14th Avenue. Thanks to webdog for the tip. Added 10/24/04. map | site

    61 Kona Shores Ice Cream: 1206 Masonic , at Haight Street. Added 10/24/04. map | site

    62 Cafe 16: 3170 16th Street, at Valencia. Thanks to Mike for the tip. Added 10/24/04. map

    63 JJ Dessert House: 1525 Irving Street, at 15th Avenue. Thanks to Benjamin for the tip. Added 10/24/04. map

    64 Sit & Spin: 4023 18th Street, at Noe Street. Thanks to Adam for the tip. Added 10/24/04. map

    65 It’s Delectable: 4416 18th Street, at Eureka Street. Simon reports that this cafe doesn’t provide wi-fi service, but it’s within range of an open wi-fi access point named “SMC.” Thanks to Simon for the tip. Added 10/24/04. map

    66 Polkan Cafe and Deli: 1754 Polk Street, at Washington. Ask the owner for access and he will provide it with purchase, according to Marissa, the Thanks to Marissa for the tip. “The owner is a russian immigrant and extremely nice (he gives cans to the chinese ladies) but has been struggling due to competition from the many dining establishments nearby,” says Marissa. Please patronize Mr. Polkan’s place! Added 10/24/04. map

    67 Coffee Break: 4601 Geary Boulevard, at 9th Avenue. Thanks to Jacob LaBay for the tip. Added 10/24/04. map

    68 South Beach Cafe : 800 The Embarcadero, near Townsend. Thanks to Danfuzz for the tip. Added 10/24/04. map

    69 Notes from the Underground Cafe: 2399 Van Ness Avenue, at Green Street. Thanks to bill for the tip. Added 10/24/04. map

    70 Tully’s: 303 2nd Street, between Harrison and Folsom Streets. Thanks to David Kapp for the tip. Added 10/24/04. map

    71 [NO LONGER OFFERS WI-FI] The Reverie Cafe: 848 Cole Street, at Frederick Street. Added 10/24/04. map

    72 Royal Grounds: 2060 Fillmore Street, at California. James Hall reports that this cafe doesn’t proide wi-fi service, but it’s within range of several open access points. Thanks to James for the tip. Added 10/24/04. map

    73 Cafe de la Presse: 352 Grant Avenue, at Bush Street. [This has been one of my favorite cafes for years. It’s across the street from the French Consulate and it draws many Europeans. It’s definitely the most European-feeling cafe in San Francisco. Will wi-fi alter that? -Sean] Added 10/24/04. map | site

    If I missed a cafe, or if one of these cafes closes or begins charging for Wi-Fi use, drop me a line and I’ll update the list: sean[at] (Remember this is a list of free Wi-Fi cafes, so please don’t contact me about cafes that charge a fee for Wi-Fi usage.)

    Czech this out: Lloyd Nebres spent a day bouncing from one wi-fi cafe to another across San Francisco, posting photos and dispatches along the way to create a little travelogue.

    The folks at Beast Blog are putting together a list of free wi-fi locations in the East Bay.

    Here’s another list of free Wi-Fi hot spots throughout the Bay Area and the world:

    And here’s a list of open wireless nodes that Bay Area people have set up, mostly in their homes.

    Join the free networks movement! Details:, and the Bay Area Wireless Users’ Group.

    Wi-Fi Internet Telephone

    February 23rd, 2003

    I want a small, cheap mobile device that:

  • notifies me when I’m within range of an open Wi-Fi (wireless Internet) signal, and:
  • allows me to call any telephone number on the planet free of charge, or nearly free of charge, whenever I’m within range of a Wi-Fi signal, via a simple numeric-keypad interface.

    (Services like PhoneFree and Net2Phone already let you make very cheap calls to worldwide telephone numbers, over the Internet using a personal computer. Now that Wi-Fi signals are becoming so widespread, a small, cheap device dedicated to this application would be extremely handy.)

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