Danah Boyd is organizing a wiki for the timeline of social networks.  I think this will turn out to be an excellent reference document.

Looks like Ramit Sethi's PBWiki.com is getting adopted pretty well.  I've used it within the team to collaborate on a couple tasks (we make it a point to use as many wiki, bug-tracking, project management, collaborative tools out there to get a good feel for other successful software apps).  PBWiki has excellent usability and UI... something we need to improve on for MyChurch.