That's how San Fran IS doing it, actually. (Score 1)

I'm posting this through SF's small-but-growing grassroots WiFi project called Free The Net. It's a venture headed up by Meraki, a company that makes access points for WiFi-meshing purposes. As far as I understand, all bandwidth is provided by AT&T. Meraki sets up the main APs, and then asks users who can see the signal to set up a repeater somewhere, such as outside their house or on a street-facing window. The repeaters and APs discover the network and can automatically provide redundancy if at all possible. If you're living in the right neighborhoods, it works pretty well. Best part vs. the method mentioned in the article: everything is free. No ports are closed, no traffic denied. Downside: There's a frame at the top of your browser which links to news articles (why? are they getting revenue through it?), although I'm sure it could easily be hacked around. Other downside: the ISP is AT&T.

I know people are probably familiar with the Google/Earthlink deal falling through in SF, but this somewhat unknown project is taking off; so far, I'm pretty impressed.