Pre-paid gas cards

UPDATE (7/17/08): MyGallons.com will give refunds to nearly 6,000 customers, and current customers will be offered a free year's membership.
UPDATE: The Better Business Bureau has given MyGallons an 'F' rating. As of this update (July 9, 2008), MyGallons was planning to meet with the BBB for a reevaluation.

A Miami-based company called MyGallons is offering you an opportunity not unlike the USPS does with their Forever Stamp. Pre-buy gasoline at the current price and fill up later without paying the higher prices. The company has no limit on redeeming the gas; so say you buy now at $4.07 and a year later gas is $7.20 (don't laugh, while it is exaggerated, it's not that farfetched), you save $3.13 a gallon! There is an annual fee for the service and about 95% of gas stations around the country participate.