An intelligent credit card incudes a keypad for inputting numbers and other information, a processor for controlling the operation of the credit card, a power source, and an output device for selectively outputting the credit card number when the card is activated. The output device is a magnetic strip....http://www.google.co.uk/patents/US6188309?utm_source=gb-gplus-sharePatent US6188309 - Method and apparatus for minimizing credit card fraud
