I am a HUGE believer in building consensus, but The Wisdom of Crowds is starting to make be rethink the approach a bit. I just finished reading, ok listening to the audio version on my bike ride into work, James Surowiecki's latest book.
1. There is a diversity of opinion
2. People are not overtly influenced by others in the group
3. Some "fair" aggregation system is at work
Surowiecki argues that these elements allow you to tap into the collect smarts of the group while canceling out their errors.. Doing things like spending tons of time consensus building often has the result of creating less diversity in opinion and thereby misses out on the collective wisdom on the group. While I don't think this applies universally, it is some thing that is making me stop and think more before doing the 100 items consensus building check list.
Rather than consensus, Surowiecki suggests using a mechanism such as Prediction Markets to make decisions. Markets like the Hollywood Stock Exchange. I'd love to participate in a market around predicting the raise of a given programming language (Java, C#, Ruby, Python,??) or programing methodology (Object Orientation, Rails, Linq, ??) or say the ship date of Orcas... It would be really interesting to see what the "wisdom on the crowd" is here.