I was once, kind of bullied, not enough to affect me throughout a day, just a moment of frustration, I think I got rid of the bullies by thinking outside the box, and focusing on what really was going on, and I just pretty much had a fight with them and found weak spots of them, (mentally this is) and I prodded on them spots until they realised I wasn't a suitable target.
Also one time a teacher bullied me a bit, but then I just focused on his weak points, telling him he was in a dead-end job, and that he feels he can pick on kids particularly because he was once bullied as a child before,(I just took a shot in the dark with that one, turned out it was true).
Also I agree with Quik, get into a fight, and you wont be bullied.
Common sense is the majority of verbal bullies weakness. This is how I avoided bullying for most of my life. However, physical bullies will just laugh it off, and call you a smart ass before attempting to pound you into the ground, in which case you have to hold your own in physical conflict if it comes to that.
After that, you're just not the right target for bullies, makes you feel better about yourself in the end if you best them in every way possible.