I once was late with a payment...my fault.. so, I called the company US Bank and asked for late fee & interest cancellation. They granted it. Then I asked if they had a lower rate for good credit customers. Without missing a beat the woman says, "Yes Mr. XX, we will offer you a lower rate of 8.99%" iirc. I think their normal rate was 12.99 or 14.99. This was a while ago, before the financial meltdown.
Moral: You don't ask, you don't get.

There was a time years ago (kids, kollege, kars etc) my cc debt was north of 10k. I started jumping from card to card with a 2% transfer fees and zero interest for 18-24 months. At end of term, switch back & so forth. Point is you must pay on time and you shouldn't use the credit card for other purchases.
I still get the CC checks from 3 or 4 banks almost monthly asking for account transfers. No mo!

Save. Don't borrow.