If you've not heard of David Bollier, now is as good a time as ever.
Bollier is an author, activist and blogger that spends a lot of time researching and thinking about the commons. He has written a number of excellent books looking at ways in which economies and communities can transition to commons based systems.
From his latest book Think Like a Commoner:

 In our age of predatory markets and make-believe democracy, our troubled political institutions have lost sight of real people and practical realities. But if you look to the edges, ordinary people are reinventing governance and provisioning on their own terms. The commons is arising as a serious, practical alternative to the corrupt Market/State.
The beauty of commons is that we can build them ourselves, right now. But the bigger challenge is, Can we learn to see the commons and, more importantly, to think like a commoner?

Recently Bollier gave a lecture in Athens about the emerging commons economy in Greece post collapse.
Here is a link to the English lecture.
And here is link to Bollier's blog.