The method can stop thieves in two ways. Those who copy down your credit card information will find that your account number and expiration date is not enough to place an order. And those who actually steal your physical card will find that they still don't know your pin.

While the cards house a 3-year battery, we're just hoping that they can stand up to a good pocket sweat. Because when we're roasting away in the summer sun, we need ice cream money to floweth from our plastic like a refreshing, icy deluge. [ITPro via gadgetell]