Tribes
And while we are at the topic of tribes and somehow stuff magically appears in front of me (or gets send to me by awesome people) there is this really eye opening interview at wired with the author of the book "tribes" explaining what a tribe is and why its so cool to embrace them.
Wired: You've said that a tribe doesn't have to be encouraged to connect, they want to connect with each other. And that you as the person in the center aren't required to do anything.
SG: That part's not true. It requires you to do a great deal. But what you don't need to do is sell people on the fact that they want to connect. That's human nature. We want to connect with like-minded people. What you have to do that's very difficult is create the platform –- whether it's a cocktail party or a technology -– where people can get over social friction, where people can make connections that would ordinarily feel awkward.