Iconocast is a good podcast from Jesus Radicals. They have a good interview with Jonathan Moyer regarding the Groupee, an alternative monetary exchange implemented among a group of Mennonites in Colorado.
Probably the best part of the interview comes when Moyer explains the rationale for such small-scale implementation of his group's ideals. Basically they found it better to do something themselves than to lobby the political powers to align public policy with their own. In that the Groupee reminds me of the behavior of the early church. When faced with a need, they did not revolt against Rome and establish their own government, nor did they petition their proconsul to implement social welfare. Rather, they took it upon themselves to help themselves, sharing wealth and serving each other as needed. Besides being practical, I think it may be the right approach in general to Christians resisting unjust structures in society.