The SIM cards in cellular telephones might be smaller than a postage stamp and less than a millimeter thick but that hasn't stopped South Korea's SK Telecom from cramming all the major components needed to run Google's Android OS inside one of them. The carrier's Android SIM, a prototype of which is on show at this week's Mobile World Congress in Barcelona, includes an ARM-based processor, companion memory and 1GB of flash memory to store the OS and other data. SK Telecom envisages such a SIM card could be used between a number of "dumb" terminals -- devices that have ancillary peripherals such as a screen and keyboard but lack a processor and pre-installed OS. The SIM card uses the USB 2.0 interface to communicate with the terminal. All of the user's applications and data are stored alongside the OS in the SIM card, so the user's desktop could be transported between devices by switching the SIM card between them. For example, a PC desktop could be...