Incidents like the one Dan Gillmor points to reminds me that I need to put more thought into noise control. Let see…
One idea is cookie sharing combined with cookie persistence. Cookie persistence works by allow people to download and save their cookies so they can restore valuable cookies after cookie wipeout or if they change machines. Cookie sharing is one cookie holder giving part of the rating they earned to another. It's like giving some of your voice to another person whose opinions you agree with or appreciate.
A lot of room for creativity in this area.
Update:
Flip-side of the Cookie sharing is mutual destruction which requires giving up part of your rating to degrade another person's rating. I am still clueless as to whether such small set of rules will lead to a stable world instead of something that will blow up. Still, I enjoy working with combining simple rules to build complex systems, probably because of my physics background.
Another thought I had was that, for systems like Wikipedia, unbiased views are sometimes either not possible or premature. In such cases, I think the right thing to od is to record multiple biased/opposing views to capture the conflict in its raw form instead.