I wouldn't expect the iPhone to ever assume a POS type feature set. However, I did find it interesting Apple was using MSFT IP in such an obviously customer facing role.

Oddly enough, I was wandering around in chinatown in sf with some friends during WWDC last June talking about the possibility of building an accessory for iPhone that did exactly that just for fun. Walking around with a small device attached to your iPhone to scan things and swipe a credit card on the spot to sell a product, et cetera.

Sorry, just a bit of deja vu. The Apple retail friends I know all hate these windows mobile devices though..but I doubt iPhone OS would be any better (ughhh I'm hating on 2.x right now, so many problems from both a user and a developer perspective).