when someone clicks on that 'scales' icon underneath your avatar, they can give you a reputation, either approve or disapprove. like if they like one of your photos you posted, youll get a good rep, or if you help out someone, they mite give you a good rep.
and i think you have to get about 50 maybe? i think it has changed lately since i joined. i stopped being a newbie at about 35 posts (i THINK)
hope that helps ya :thumbsup: