A device, a method and a system for portable data storage and transfer through a simplified device interface. The operations of the device are restricted, in order to increase the ease of use of the device, and in order to provide certain core functions. These core functions include reading data, writing data and exchanging data with a similar device and/or with an external computer. The device features a minimal set of hardware components for accomplishing these functions, such as a data processor of some type, a memory storage medium or media, and a data exchange mechanism, which may optionally be an infrared port for example.