Beware of the fine print. Cards like Next Card offer 9.9% "fixed" regular APR on their web based card, but with a catch. After 1 late payment they raise the APR to over 17%. After 2 late payments they raise it again to over 21%. A "late" payment is one that posts even 1 day after the due date regardless of when it goes in the mail. I no longer have a "low interest" card but now have one of the highest APR cards on the market. I will be paying them off and no longer doing business with these people.
All banks practice locking you into higher rates, some are more obvious than others. Whenever you get a low rate, the intent is to lock you into a higher rate, if possible. Always, pay the high rate cards and try to have multiple cards to take full advantage of the "teaser rates". Profit from the experience. http://www.creditsense.com
I take advantage of the bank's online payment system, where the payment is debited right from my checking account, and is always posted on the second business day. This saves any USPS hassle!
My rule #1 on paying credit cards is to pay the bill as soon as I get it. No need in hanging on to it. If you can't pay it when you receive it, mail it at least 7-10 business days ahead of time or take advantage of their free electronic payment service. Protect yourself. Regards, JP