Through tomorrow, Walgreens is offering a $15 mail-in gas card rebate when you buy three (3)or more American Express gift cards. This is an attractive deal whether you intend to give the gift cards or simply use them yourself for some holiday shopping.
You should be able to buy three (3) $25 American Express gift cards, for example, and then mail in the rebate request for a free $15 gas card.
In addition, if you've snared any of the beer rebate forms - I think from Coors - offering a $15 cash rebate when you buy $100 in gift cards, this could be even more attractive. Just make sure you buy at least $100 worth of American Express gift cards if you intend to do that deal.