BetterMeans.com has recently released a web based "open and democratic project management tool", and it looks very promising. Along with basic tools like a wiki, discussion boards and document storage, it has array of tools for collectively prioritizing tasks, estimatating work item complexity, reviewing work, allocating compensation, and voting on motions. The entire system seems to be built around a set of values that enforce and promote transparency, accountability, cooperation, pragmatism, and distributed leadership.
I could imagine it working with open source developers, maybe some collaborative scientists, activist collectives, and dnew not-for-profits. I look forward to seeing how this tool evolves, what kinds of groups use and what for.