I read with interest Sam's thoughts on collaboration and the discussion that started from there. It's interesting because its something that I agree with, but, alas, don't have an easy solution to, either.
Something I find even more interesting is the fact that while working around a project might work well and build a collaboration environment, not always does it also mean that a real community might appear from there. For example, some Open-Source projects I've worked on have been very succesful (at least imho) and collaborating on them was great, but not much community (at least as I see it). Whether that's good or bad I still don't know.
Something else that really caught my eye in Sam's piece was his comment that "
seems very difficult to get people to collaborate freely and consitently in a medium where they feel like they have an obligation". While I agree in principle, I also find it ironic that when collaboration is built around a project, then the obligation to contribute is almost implied by definition . To be able to collaborate to a project, you need to do something. Else, how are you collaborating?
 Note that this doesn't necessarily mean contributing code