To use Apple Pay,users have to already have a card saved on their phones, which can either be one already stored in iTunes or one you add yourself. Then you just hold your finger down on the iPhone's fingerprint reader, and hold the phone near a special card reader.
So is this the revolution we've all been waiting for? Maybe. If it works consistently, that's a lot less time than pulling a card out of a purse or wallet, swiping it, slotting it back into place and then stuffing a receipt into your billfold or pocket.
Of course, demos do tend to run smoothly. In my experience with Touch ID, Apple's fingerprint reader, things haven't always been so easy. As my Post colleague Brian Fung reported, those who buy the new phones will get the chance to try it out for themselves in October, at major chains such as Whole Foods, McDonald's and Subway. Fast food, indeed.