If you haven't used one of your credit cards for months or even years, don't be surprised when you receive a letter in the mail notifying you of an account cancellation. Some credit issuers may be kind enough to provide advance notice; however, in many cases you won't learn of the cancellation until after the fact. And yes, they can do that for now - it's legal.

Adding a child or spouse as an authorized user to one of your credit cards, also known as piggybacking, can help them build credit. Of course, that's as long as you continue to maintain a low credit utilization while making all your credit card payments on time. Miss a few payments or drive up your credit utilization ratio by carrying large balances, and you can do some major damage to your authorized user's credit scores too.

Small Business Saturday 2011 is just one week away, so don't forget to register your American Express card this week! Trust us, you don't want to miss out on this opportunity.

After registering, all you'll need to do is spend at least $25 at a small business next Saturday, November 26th, and then Amex will provide you with a $25 statement credit. No strings attached—it really is that simple.

You're a responsible credit card user. You live within your means and pay your balances in full each month.

It's likely you even have several credit cards in your wallet, although the majority of your monthly expenses are charged to the one that helps you bank the most rewards. As for the other cards, you keep them active to help boost your credit score and serve as backup in case of emergency.

What's wrong with that? Well, in the past you had little to worry about. But times have changed.