For those who want to carry around their USB flash drive around with them in a discreet manner, the Freecom USB card fits the bill perfectly. Coming in the form of a credit card, it measures just 2mm thin, fitting into just about any wallet comfortably. The USB plug has been integrated into the card and can be folded out when needed. Storage capacity ranges between 256MB to 4GB, depending on your budget. This goes one up on other similar offerings by being slimmer and securing your data using password protection and encryption software. It is compatible with both Windows and Mac OS X operating systems.
Source: Yanko Design