You've probably seen contactless payment terminals before. They're used in many stores, restaurants, and other locations, with either a smart credit card containing a secure memory card or some sort of fob being used to make the payment. You just wave it at the terminal, and you've paid your bill.
Visa and DeviceFidelity are working on a way to let iPhone users make payments by waving their iPhones in front of contactless payment terminals. They'll be offering an iPhone case with an embedded secure memory card that hosts Visa's payment application, Visa payWave.
Any place you find a Visa contactless payment terminal, there will also be a potential spot for iPhone users to pay for goods or services using their Visa credit card account. Security is still important: Visa notes that the mobile payment application can be protected with a password, and that users will have to treat the case as if it were a credit card, calling the bank if it gets lost or stolen.
Market trials of this service are expected to start this summer. It's an interesting proposal, but we'll have to see what the case looks like. And of course it's only for Visa customers so far -- customers of other card companies will have to figure out their own solutions.