Citibank also offers a "1 mile for 1 $ spent" debit card if you pay a higher annual fee - $65 (as opposed to $25 for the "1/2 mile for 1 $" card) & you also get a 4,000 mile sign-up bonus (as opposed to 2000 miles with the basic debit card).

Note though that with Citibank's AA debit card you only earn miles on "signature-based purchases" (when you use the card "as" a credit card), any purchases you make using your PIN number will garner you no miles. This is the only debit card with a one-for-one ratio (However I believe Chase will give you a "one-for-one" debit card earning Continental miles if you keep a humongeous average daily balance in your account - about $20,000 or $25,000 I think).

Obviously, if the Citibank "one-for-one" debit card will work for you, that is really the best option.

My $0.02

-MJ