Often used as a kidding face in a chat room or forum to show others that you are just joking around.
I choose to use the bracket because it's more original than the played out parenthesis smiley.
Girl: Nothing. I'm going crazy!!
Guy: Yeah, that's because you ARE crazy! ;]
1. being playful--flirting (just like a wink in real life)
2. showing that you are just jokin' around
lilllboy: baha u crack meh uhp
crazee: hehe you crack me up 2!
lilllboy: bahaha, u also make somethin else go 'uhp' ;]
lilllboy: i cant believe u got banned, lolz
crazee: i knowss! lolz, its so dumb!
lilllboy: chyeahh,you ish dumb too! ;]