Through March 15th, all American Express cardholders can go to https://enroll.amexnetwork.com/US/iTunes2011/ to register your card to get 5 free song downloads from iTunes. The way it works is you pay with the American Express card you registered, then the cost will be automatically refunded to that card.
Happy listening! Have you ever heard King of Anything by Sara Bareilles? I am listening to it right now and love it!