the little green boxes in the left corner of a post. the more boxes someone has the more rep they have recieved from thier peers. green is positive rep, red is negative. if someone helps you or particularly thrills you, maybe geves you some bad advise, give them good or bad rep. click on "My Rollitup" and all the way at the bottom you can see who has left you rep. but have some cojones, if you leave neg rep leave your name.
go look, im gonna rep you.