Apple has launched iTunes Pass, a method using your iPhone in an Apple Store to reload your iTunes account, in Japan.
Apple launches iPhone mobile payment system in Japan
The system lets users add money to their iTunes account, and uses a barcode to complete the process. An Apple Store rep scans your phone, you pay them (presumably using any method, including cash) and now you can go buy apps without charging them to your credit card.. Llimiting it to Japan hints that this is a trial program so Apple can find any problems before expanding into other markets.
Apple is calling its in-store reloading system iTunes Pass, not to be confused with the iTunes Pass that lets iTunes Store customers pay for content related to s specific musical artist. The system works just like a reloadable gift card.
[Thanks to 9to5 Mac for the heads up]