As others suggested, limiting yourself to low limit cards only for credit building purposes is the way to go. Speaking from experience after an intense manic spending episode 7 years ago, I personally see credit cards as an awful terrible thing. When used responsibly they can be wonderful, but if you ever find yourself truly manic you will convince yourself that the money to pay off the large debt will come from somewhere, and you won't even think twice.

I do have a credit card now and I find myself getting angry when they keep raising the limit. I'm it's great business for THEM to have a known manic spender as a customer. The conspiracy theorist in me wants to think that they do it on purpose.