So you think that the iPod Shuffle is one of the more portable MP3 players? How about the Walletex that measures a wee bit thicker than the average credit card, using a USB-to-phono jack in order to connect a pair of headphones. This unique MP3 player is resistant to dust and water, and boasts capacities which range from 128MB to 2GB in size. The Walletex MP3 player looks set to be a promotional item only and will not be available commercially. Pricing details are currently unknown, but you can check out the press release for further details.