DeviceFidelity's mobile twist on Visa's payWave system is a nice little solution to the fact that nobody's bothered to build contactless payment chips into US mobile phones just yet -- DeviceFidelity just stuffs the Visa smart chip circuitry into a microSD card and lets you on your way. Of course, this supplants the much needed additional storage on an Android handset, and requires a chunky add-on case for the iPhone, but at least it's a start. Visa will now start allowing those payWave-enabled devices to make contactless payments at subway turnstiles and taxi backseats in New York City as part of a new trial for th
