Abstract: A wireless user terminal (10), such as a cellular telephone, includes a transceiver (14, 16) for conducting bidirectional RF communications with a communications network (32) and a data processor (18b) for controlling the operation of the terminal. The terminal further includes (a) a first memory capable of storing a data processor program; (b) a second memory capable of storing a data processor program; (c) a memory device or register for storing a flag for indicating which of the first and second memories is a currently Active memory, that stores a currently active data processor program, and which of the first and second memories is a currently Idle memory; and (d) circuitry for receiving another data processor program from the communications network and for storing the received another data processor program into the Idle memory. The circuitry operates while the data processor executes the data processor program stored in the Active memory.