Oh, and Transition Town groups are community groups based on the
Transition Handbook by Rob Hopkins, though I've heard his
Transition Companion is even better. (Those are
affiliate links.) Transition Town ideas are based in
permaculture.
Transition groups might get involved with community property, or start some kind of community
energy or business coop, though in my experience, until or unless there is a tangible
project, they are more social and education oriented than anything else. The iterations are as varied as the people organizing them.