Biog-o-matic
One of the posts in the recent Knowledge Jam on technologies for collaboration for social change suggested the CollectiveX platform as a space for creating online communities or practise.
I've just been exploring it for a client, and:
a) It looks like a really easy to set up platform with good support for RSS feed agregation, online discussions, file sharing, networking and member profiles. (If you're looking to be up-and-running inside a couple of hours with a community website for a small team - and you're not anticipating needing to add any particular advanced features in the future - then it seems well worth a look.)
and
b) It has one of the most fantastic features I've ever come across in an online community system. It writes my biography for me.

I recently co-designed and fascilitated a series of dialogue events for 

