Hehe. The proper name would be Wireless community mesh network. There are such networks all over Europe; the primary goal is not file-sharing, but some file-sharing is, of course, taking place.

I'm involved in a local effort to build such a network in my city; eventually we'll be connecting the network to an already established VPN that connects different cities. Later on, that VPN may be merged with other European networks, and in the end we hope to become mostly independent of traditional ISPs.

German Homepage: www.freifunk.net
English Info (somewhat lacking): http://wiki.freifunk.net/Kategorie:English