I've been fascinated by the way Cmdr Taco and his crowd have built a huge discussion site that seems to be able to keep a good conversation going even though it has a transient population of tens of thousands of people. The site is (almost) entirely self regulating -- comments and responses are "moderated" either up or down in points for being insightful, redundant, interesting, funny, or toll-bait (and others). Moderation of posts is further moderated by "meta-moderators" who can recommend that a moderation by someone was wrongly assigned. The result is that the valuable contributions to the discussion tend to "bubble up" while the noise tends to disappear in the depths. It makes for a fantastic was to sift through a discussion.

Each logged in user also has "Karma" -- which can be good or bad, in varying degrees. This is an accumulation of login time, number of comments made, number of comments moderated positively or negatively, and other mysterious metrics. No one can fully define the source of Karma, of course. I was very pleased when I saw that mine had been rated "Excellent" and has stayed there. Some time later I gained access to "meta moderate". Most users can do this, if they have good karma and have been around a while. Today was the first time I've logged in and seen that I was drawn from the available pool and given "Mod Points" -- five points to use over three days in the discussions to moderate particular comments up or down. There's a reason they don't last long -- its use them or loose them so they aren't stockpiled and used to influence discussions. You also can't moderate in discussions you comment in.

The process is fascinating. If you want to understand more, look at the /. FAQ and scroll down to the "Comments and Moderation" section. Its interesting reading as its very well considering and has been reliably working for some time.