I am not a 100% sure exactly, I know that if a user has their reputation turned on in their control panel, others can add approval or dissaproval points by clicking on the scale on the bottom left under their name. The green is obviously for good rep, red for bad. Someone doesnt' like Niterydr and i had nothing to do with it
Other than it telling you how many rep points you have in the control panel, I don't know how you would view the comments left by others on yourself, but it seems there should be a way otherwise, whats the point of being able to leave one.