There are lots of examples of community-based conflict resolution models available in anthropological work dealing with small-scale and pre-industrial societies, that is an interesting place to look for some historic (and current) examples.
Another place I can think of is in the model used by the Albany Free School (and others I think...) I can't speak first-hand to how it works, but from what I understand, anyone who has a dispute or conflict can call a circle, at any time, and everyone stops to deliberate on the subject. I believe they use consensus in this process, though again, I am not 100% sure.
A slightly different take on that sort of model comes from the alternative jr high I attended. When there were conflicts in that school, a student with an issue could bring it to the support group of the other party(s) to be addressed. Support groups were like homerooms - a teacher and about 25 - 30 students. We would then ask questions of both parties and use consensus to decide a resolution. Each year we would review the student handbook as a school and adapt the various possible consequences as we saw fit.
I should be clear that this was not without a lot of problems, and was certainly not an anarchist model. Teachers did have the power to override decisions, and did so increasingly over time while I was at the school. Because it was a school, it was hardly an organically developed community, which meant that there were cliques, picked-upon individuals, and everything else you might expect from a jr high school, which, on reflection is a pretty good mirror of society. Within what was normally brought up in support groups, it was often lots of rule infractions ("ingrate threw a rotten apple against the wall of the commons,") and as such were often times very guided by teachers who used their implied authority, if not their actual authority.
As much as it was not a perfect model of community based decision making, that experience actually was incredibly influential for the person I became.
I would also recommend both the books dot did for more thoughts on it.
