Shop at any major retailer in the country, and unless you're using cold, hard cash, you'll be asked the question, "Debit or credit?" If, like me, you typically answer based on the whim of the moment, you'll be interested to know that there really are times when choosing one over the other can make a difference.

Most folks already know the major difference between debit and credit cards, of course. Debit cards immediately withdraw money from an account in which you have previously deposited funds. When you swipe your debit card, the store is checking to make sure you have adequate funds in your account. Pay with credit, and the merchant simply verifies that you have an adequate credit line. The bank pays at the moment of purchase, and you're responsible for paying the bank back.