It is a great idea that just needs the right medium. BBSs were a great medium because it took effort to find a board, connect and learn the etiquette. The early web was a great medium because it was a whole new environment to learn and explore. Wide-area adhoc wifi networks were a great medium because they had the real hacker appeal of having to find an unwanted microwave antenna to turn to a new use and search out like-minded individuals to connect to.

If you could find a medium that has the same sort of DIY/frontiersman feeling people will flock to it. Having a new world to explore and having constraints to overcome are the things that made the internet great.