I just stumbled across this while reading this month’s issue of Popsci. Have you ever worried about a crook snagging your card and ordering high end goods over the phone? Well, the Beepcard contains a prototype paper-thin speaker, microphone and voice-recognition chip. In order to use the card the user must speak into the card – yes the card – and if the recorded sample is a match, the card will send “high frequency, hard-to-fake beeps over the phone or a computer microphone, signaling the credit card company to authorize the transaction”. I am not sure if it can have multiple users, but Beepcard is market ready and they’re currently looking for partners.