I have activated the Reputation feature. There is a small badge under each post that allows you to approve or disapprove posts. You may use this feature when you find it fair to affect the reputation of other users.
You must have 50 posts before you can approve/disapprove the posts of other people.
Reasons to Approve posts (add points):
Helped me
Made me smile
Answered my question in full
Reasons to Disapprove posts (deduct points):
Aggressive post
Bigoted attitude
Offensive joke
Etc