Would love you gentel opinion on a related experiment we have with crowd moderated forums. If each group member rate just one new post, the group as a whole can collectively filter through thousands of ideas. See more informaion here http://blog.postwaves.com/about
Dynamics is very different than Reddit since each new post is sent only to a small random group of users to vote whether it should be public, no one else sees the post before that, and voter dont know who the submitter is so votes are less biased.