Or you could do your credit card purchasing with a credit card that offers you gas rebate rewards. With the cost of gas spiralling through the roof with a speed it hasn't had since 1972, gas rebate credit cards are becoming a more and more popular option for people looking to save a little money at the pumps.

And it's no wonder. With the average cost of filling your gas tank hitting $30 and up, saving as much as 10% every time you fill up is a powerful incentive to abandon 1-5% cash and reward point rewards in favor of a credit card that pays you back in gas. To make the deal even sweeter, many of the best deals are on standard credit cards that will pay you a rebate on any brand of gasoline that you purchase.

The rebates range from 3% to 10% cash back on your gas station purchases. They're paid out by a variety of methods including gift cards, discounts on other purchases and credits to your account. Of them all, the cards that apply the gas rebate directly to your existing balance seem to make the most sense on the surface. By applying the rebate amount to your existing balance, you're also lowering your monthly interest payment by lowering the amount on which the interest is charged.

Among the credit cards that offer rebates on any purchases made at any gas station, the AAA Diamond Advantage Visa from MBNA appears to be among the best. It offers a 5% rebate on any brand of gas purchased, plus one reward point for every dollar spent. The reward points are automatically applied to your account. When you earn 5,000 points, the company issues a $50 gift certificate for AAA services.

If you're willing to confine your purchases to one brand of gas, you can earn 10% off all Marathon purchases for the first 60 days followed by a 5% rebate for fuel purchases thereafter. Shell MasterCard, issued by Citibank offers 5% rebate on gas purchases and 1% rebate on general purchases. The amount saved is credited to your card statement every month. In addition, each year that you make 9 or more purchases of Shell Gasoline, your annual fee of $20 is waived.

Your best bet in choosing a gas rebate credit card is to study all the offers and figure out which works best for you. Gasoline is one of the larger monthly expenses for most people. Being able to cut your gasoline bill by 10% or more per year is certainly worth doing a little credit card research before making a choice. Don't forget to average in the credit cards that aren't specific to gasoline rebates. A standard credit card with a great cash-back program AND a rewards points system could be your best choice of all.