"Ingenico's research teams have developed the world's first-ever terminal accepting a payment on an iPod. Ingenico’s i5100 terminal integrates with Atlantic Radio System’s FM data extraction module, allowing it to communicate with the iPod via the FM band while enabling users to pay for goods using their MP3 player. Ingenico demonstrated how, in a hypothetical future, travellers could book plane tickets and receive them via MP3 format by e-mail. They would then just need to store the MP3 receipt on an iPod before going to the airport."
-- press release