The Bay Area Wireless User's Group ( http://www.bawug.org/) is one of several wireless groups in the San Francisco Bay area. It grew out of PlayaNet, the free 802.11b network of Burning Man (see http://www.playanet.org/ and http://www.burningman.com/ for details). Since a huge percentage of Burning Man attendees are from San Francisco, it was only natural that the 10-day-a-year playa network geeks would want something to work on for the other 355.
While they focus primarily on education, the BAWUG group has made great contributions to the global wireless community through their web site and regular meetings. Members have facilitated group equipment buys, done some stellar work on solving the labyrinthine FCC Part 15, and are doing quite well to fulfill their collective mission:
BAWUG provides help with developing infrastructure such as: mailing lists, labor, education, etc. including monthly meetings. Our current goal is to publish documents to assist the wireless community, secondary is to build a community grassroots network.
They have also just brought the first ever real-world Wireless Hardware comparison database online. This is a free (and invaluable) tool for anyone using commercial APs. They are collecting actual performance statistics and data (including range, throughput, cost, and ease of use) from every piece of hardware they can get their hands on. They are keeping the database current through user submissions. Be sure to check out their site for details. If you're ever in the SF Bay area, I highly recommend attending a meeting. They consistently draw 50+ people, and they have been host to an interesting collection of speakers, ranging from wireless industry jockeys to Internet startups to hardcore RF hacks. It has been well worth the twohour drive from Sebastopol each time our group has attended.