[mikegreenberg]

These sorts of sites are hard, because you really need to have a steady flow of traffic to make them interesting for anyone. These sites will typically have a way to ping their users when there's something interesting on the site instead of requiring them to sit around and wait.

Also, you'll have to work really hard to make sure the site attracts people stay as long as possible... maybe with some game element involved.

Maybe when the site is dead, users can be contacted and meetings arranged out-of-band. Or arrangement specific times when users can come to the site for a specific reason or event. I'm really not sure. :(