I used to, a bit. I've only done it three or four times, and I haven't for a couple years. I still think about it a lot though.
If you want to stop, I think that the best method is to set up a "buddy system," so to speak. Whenever you start wanting to cut, tell someone. You probably want to set up something like this ahead of time with someone you can trust not to freak out on you. If there is a reason you want to cut, talk about it. In the case of lack of a person to talk to, journal. If you don't trust anyone enough to tell them that you are a cutter, just get away from sharp objects. Go for a walk or hang out in a coffee shop or something. My favorite technique for preventing self-harm is to come up with excuses. For example, "I would cut/hurt/whatever myself if such and such wasn't the case." I can get away with pretty lame excuses, because it never became a habit for me. I don't know if this sort of thing would work for you.
Point two. How do I say this? ... I think it is part of human nature to want to destroy things. The fact that you don't turn that "instinct," so to speak, outwards, at other people and objects, demostrates that, to put it somewhat cornily, you are a good person.
I'm not saying exactly what I mean. PM me if you want clarification.