Fon.com is an intriguing, and apparently growing in popularity, concept and commercial solution in building community-based public wifi networks. Basically, FON enables your WiFi access point to securely share your connection with other FON users. They share, you share. This means that you give up a little bandwidth on your box, but gain a world (literally) of free access points.
What makes it even more intriguing is the release of a new FON access point, called LaFonera, that provides 2 built-in networks and neatly supports the FON community concept. (sells for $14 including shipping, but read the fine print!).
You can watch the LaFonera launch video or read their blog.
The web site isn’t quite exceptional – but the concept may just be!
Tamir Levin

With regards to social wifi networks. A company called Truphone (http://www.truphone.com/), launched their Beta product at VON in Boston.
They have achieved Mobile Voip or Moip. On the Nokia e-series and soon on the n-series phones. These phones have Wifi built in. Eventually all Truphone users will share each others networks.
True social mobile network