As reported in an earlier post, the GoPayment app was there at birth of the Palm Pre.  Now its made its way onto the iPhone app store.  Nice work IMS GoPayment team!  You can download the app for your iPhone or read more on SNAP. Sounds like its not as easy as the Pre app though--you must hand-key in everything (amount, payer's card #, expiration date, security code, billing ZIP) until Apple relinquishes their stranglehold on the bluetooth support--the card swiper (shown below) that works on other phones will not work on the iPhone app...yet.