A flash memory mass storage drive stores user files in a convenient credit card sized drive. Embodiments function as both a credit card and a mass storage drive. Communication may be through a host interface connector such as a USB connector, a magnetic interface, a smart card interface, and/or a near field communication interface. In certain embodiments the drive comprises a portion that is sufficiently thin to be swiped through a standard credit card, ATM, or point of sale device. The USB connector of the drive can easily be plugged into even a crowded receptacle of a host computing device.