Headset system with user-configurable function button

A headset providing audio input and output for a mobile device includes a microphone and speaker. An RF transceiver performs wireless communication with the mobile device. One or more buttons are configured for push operations to control operation of the headset, the mobile device, or both. A processor is configured to process a signal input from the microphone and output the processed signal to the RF transceiver, process a signal received from the RF transceiver and output the processed signal to the speaker, and process a signal input according to the push operations of the one or more buttons. At least one of the buttons is configurable to actuate a selected function. A memory associated with the processor stores program instructions for executing a plurality of functions, wherein the selected plurality of function is selected in response to user input via a user interface on the mobile device.