In Taos, NM, I was part of the Taos Peace House. We also organized a major city-wide peace event: Taos Peace Week. We used Formal Concensus to help us coordinate and organze. At times, we had around 25+ people involved. What makes Formal Consensus so effective is the processes it uses to help create concensus decisions... the facilitator, the time keeper, the agenda planner, how proposals are dealt with, etc. Below is a link that goes into these details. Thousands of groups around the U.S. and the world use this technique. While we may just have 3/4 majority voting, using some of the processes of Formal Consensus could improve our decision making process.
Onwards - Tom Ray
Here is some link about the formal consensus process:
http://www.learningmethods.com/pdf/on%20conflict%20and%20consensus.pdf
http://ase.tufts.edu/coalition/tsad/iv.html
Most people do not understand what concensus means, or even have experienced it. Some have not had good experiences with a concensus process, probably because it was not structured in a formal way with guidelines & rules, much like the Robert's Rules of Order. One thing though when a group decision has been made through a formal consensus process, the group coordination and organizing is better because everyone in the group is going with the flow of the decision, and it helps prevent creating fractions within a group.
Here is some thoughts on consensus from Starhawk, a world-wide activist and organizer:
http://www.starhawk.org/activism/trainer-resources/consensus.html