The little thumbs (or thumbs down) on the under the name allows you to give out (or take away) points. (Green and red thumbs.) (I would never give a thumbs down except for a racist or sexist post.) However, you are limited to only giving a certain number of points per day (or week), not sure on that one. The reputation points also appear under the name. I give them for particularly good or helpful posts. Never felt a desire to take any away.
--Jay
