Bro, i feel for ya. there is a fair bit of bullying and the like at my school and when ever i see it i try to stamp it out. there are various ways of dealing with it.
Firstly dont get violent unless it is truly and absolutly nesacary. this rarely solves the problem and usally just adds to it.
Try to use more "verbal violence" i.e. some of my favorites are "Wake up to your self you simple c*nt" or "Big man, real big man does that make you feel better big man?"
Yeah, use your imagination, if you can, try and find something incriminating about them like say imbarrasing moments or weird habits, genitalia size etc.....
But really, the best thing to do is stand up for your self. Dont let people walk all over your because if you cant deal with it now, its gona get harder and harder as you get older.