The WiFi networking coupled with mesh network e.g. Freifunk would allow a community to have good networking independent of ISPs. The peer-to-peer network file sharing programs will work just fine over a mesh of that type. It's more viable than what we did with our ham radio packet networks in the 80's.
There are alternative firmware loads for the Linksys WRT-54G router that natively support Freifunk. I don't recall whether that is an AODV or OLSR mesh. The routers that support it were Linux based. Later board revisions moved to a different OS and smaller memory footprint to save money. The best configurations are running dual frequency bands. A "backbone" on 802.11a goes router to router. Local connectivity is achieved on 802.11b/g on 2.4 GHz. The antennas are small and easy to place high on your house.
Only problem with Wifi is the limited reach it has. You would literally need every other neighbor to be setup the same for it to work.