Here's an article showing great credit cards with rebates for gas
purchases - up to 10% cash back!
I already signed up for the AMEX, and get 5% back. Also the costco no-
fee AMEX gives 5% cash back.
http://www.desicrazy.com/2008/07/28/top-credit-cards-for-gas-purchases-up-to-10-cash-back/