I've been lucky enough to be part of an exciting experiment. Several months back, Seth Godin set up an invitation-only website called Triiibes. This accompanied the preparation for his new book Tribes. To get a glimpse on what's going on there, check out The Daily Triiibunal.
This group is inspiring, and moreover, productive! Together with the book launch in October, the group released the first accompanying eBook, the Tribes Case Book. And they just released the second one, the Q&A Book. Especially the second one is amazing in quality and done just by volunteers who are passionate about Tribes. Check the books out, they are free and quite amazing.