Oh, girl, I hear you!
In theory, I agree that cutting up your credit cards may be a good idea. However, I really don't think that it will solve the problem. It's kind of like telling someone who's addicted to crack, "Well, stop buying crack" or "Hide your money so you can't buy crack." It sounds good, but really is not going to help if you *really* have a problem. Even if you cut them up, if you have a credit card bill and you know your expiration date, you can shop on line all day (believe me, I know!) -- what I'm saying is that if you REALLY are a shopping addict, you will be clever and find ways around it.
Apparently, there's even a name for shopping addiction -- oniomania. I don't know if it really qualifies as an "addiction" or whether it is more a result of depression. Here are a couple links you may want to check out:
http://www.indiana.edu/~engs/hints/shop.html
http://www.galaxyofhealth.com/nov00/shopping.html
I don't know how helpful any of this is, but you can find more stuff on the internet that may help. I think that if you are really, really bothered by your shopping and feel that your spending is out of control, counseling may be in order. That way, you can deal with the underlying issues that are making you shop. Cutting up your credit cards may be a quick fix, but I really think that unless you address *why* you're doing it, the problem will still be there and will end up manifesting itself in other ways. It's really not about money and not about getting rid of credit cards, IMHO.
Good luck!