With the price of oil climbing back above $100 a barrel — and political turmoil in the Middle East hinting at even higher fuel prices to come — it may be time to take another look at gas rebate credit cards

Rewards credit cards are among the most popular credit cards, and for good reason. However, according to a new study from economists at the Federal Reserve Bank of Chicago, enrolling in a credit card rewards program may also increase spending.

Card issuers are promoting rewards cards programs as they work to keep existing costumers and attract new ones.

American Express and the online-game company Zynga have partnered to create a rewards program allowing cardholders to use rewards points to purchase virtual goods in online games like Farmville and Café World.

The new rules of the Credit CARD Act, which have been phased in over the last year appears to have been successful in closing the door on many of the “deceptive and unfair” lending practices Congress set out to curtail.