After seeing this work decently well to detract people from being stupid in forums, I've decided to turn it on for a test run here as well.
You can read the admin description of it here:
vBulletin Manual or just google 'vbulletin user reputation'
To help stem off abuse, I've enabled functionality so you see who leaves you reputation - note for people who would have used this to anonymously flame, you won't be anonymous. So don't abuse the system.
Likewise, users who abuse the system will be given an infraction and repeat offenders will be banned.
This will be a test run for a few weeks and we'll see how things go. ^_^ I encourage you to leave kudos for posts that you like!
DO
-Leave positive reputation for posts you think are funny/helpful/etc
-Leave negative reputation for posts you think are excessively flaming, trollbait, or out of line
-Leave this kind of feedback for mods/admins too ^_^ don't worry about the rank, treat everybody as an equal!
DONT
-Leave negative feedback based on a grudge or because of a personal dislike with no valid reason