have you been in an apple store lately? their iphones have a speial case that acts as an integrated credit card machine. you just hand the apple rep your card, they swipe it through their iphone case, and email you the receipt. redunculous!
yep... its been around for awhile, and it eliminates the need to queue for payment at the cashier counter...
It also promotes impulse purchases... cos u may change your mind about buying the item from the moment u pick it up till u reach the cashier counter...