Abstract: A cellular phone comprises a transceiver that wirelessly transmits and receives wireless cellular signals, a display, an input device, a microphone that generates audio signals and a light sensing module that senses ambient light. A control module communicates with the transceiver, the display, the input device, the microphone and the light sensing module, and comprises a comparing module that generates a first signal when the ambient light signal is less than a threshold, a timing module that determines a duration of the first signal and a selecting module that communicates with the timing module and that selectively deactivates the display and the input device when the duration is greater than a first period.