A symbol standing for the word "at" that in turn symbolizes lazyness and stupidity. I mean, seriously, who sat down and thought up a symbol to shorten a two letter word? WHY? Your time could be better spent counting blades of grass in your front lawn. At least that might teach the retarded bastard to count! If you now anyone that abbreviates the word "at" as "@", cease all conversations with said person, as their retardedness may rub off on you.
Steve:Hey, where were you?
Bob: I was @ the mall.
Steve: ...You're dead to me. (walks away)
Bob: ...Hmm, what was th@ about? I think I'm going to go sleep in my own filth and be lazy and unproductive!
The next day Steve won the lottery and Bob was struck down by God. True story. Go Google that shit.