Several companies including Device Fidelity http://www.devifi.com/products.html are developing functionality that will enable a mobile phone to be used as a credit card. Nokia has been working on a NFC phone for some time but it looks like Device Fidelity has developed a Micro SD card that can be used in over 120 mobile phones. I’m still to be convinced that mobile phone as credit cards are a killer app but they are looking at a couple of other areas like access control.>
