A keyboard for a computer receptive to a modular or other device, and a modular touch screen device having at least one changeable virtual key, are described. The keyboard includes a connector receptive to a corresponding connector of a device such as a personal digital assistant (PDA) device. The device communicates with a computer through the keyboard in a docking mode. The modular touch screen device extends the capability of a keyboard to which it is connected in a docking mode by providing changeable virtual keys. In a stand-alone mode, the modular touch screen device acts as a truncated wireless keyboard, or a dynamic remote control, for a computer.