Rollbackprice.com is now offering the opportunity to trun your drivers license into a credit card. Not only that, but when you use your new license credit card at the gas pump you will save $.03/gallon! The program is pretty new, and it is available only to residents in and around Austin, TX.
Although losing your license would now pose double the risk, it is an interested concept. You can still find better gas pump savings by going with a gas rebate credit card though (.03/gallon vs. 3-5% savings).