A computing system comprising a pocket personal computer and a reader are disclosed. The pocket PC is credit card-sized and comprises flash memory, and optionally a processor and a GPS chip. In some embodiments, the pocket PC also includes an operating system. The reader includes a monitor, a keyboard with docking port and an optional processor and at least one input/output USB connector. A user cannot interact with the pocket PC without the reader. The reader is a non-functioning "shell" without the pocket PC, however, when they are connected the system becomes a fully functional personal computer. To log on, a user provides security information, for example, a password or biometrics, such as fingerprints. The credit card size and capabilities of the pocket PC allows a user to easily carry virtually their entire computer in a pocket for use anywhere there is a reader. In addition, the pocket PC provides security against unauthorized use, even if lost or stolen, since a password or fingerprints are required to access to the device.