If you have a credit card, you probably get those "convenience checks" in the mail. These are checks the credit card company sends without your permission. They allow you to write a check on your account, and it shows up on your credit card bill just like other charges.

Whether you use these checks is up to you (keep in mind they may have different interest rates than your standard charges), but if you throw them away, shred them first. Otherwise, you have identity theft waiting to happen in your dumpster. Think about it: if a thief gets his hands on these checks, he can start using your credit card account for his own purchases.

So if you're not interested in these checks at all, you can call your credit card company and ask them to stop sending them. Most companies will honor that, though it may take a month or two.

While on the topic of credit cards, remember that you can opt out of unsolicited credit card offers.