I guess this is the future of commerce: whip out your iPhone to accept a credit card payment wherever you are. And simply wave your iPhone to make a payment when you're buying something. TransSF Card Terminal is a free app that lets you accept credit card payments on your iPhone. The app claims to be the only one that works with any gateway and any credit card processor. And on the other end of things, a company called Zenius makes it possible to wave-and-pay: that is, you hold out your iPhone and it communicates with a point-of-purchase device in order to pay for your purchase. It requires retrofitting your iPhone with a small device. According to their press release, retrofitted iPhones can immediately conduct secure contactless wave-and-pay transactions for Mastercard PayPass, Visa payWave, American Express ExpressPay, and Discover Network Zip. They say that whereas most current NFC options don’t allow the consumer to have any control, the Zenius solution integrates a mobile wallet menu on the iPhone, allowing you to choose from a PIN-secured suite of applications such as credit cards, subway tickets, and coupons. The Zenius-enabled product is added seamlessly to the phone, and no jailbreaking or unlocking is required.