A mobile phone with a hidden input device. The mobile phone comprises a main
body,
and an input device coupled to the main body to input data and rotatably connected
to the main body between a first position and a second position by a rotating device,
wherein the input device has a visible portion with a plurality of first input
elements covered by the main body when the input device is fixed in the first position,
and a hidden portion with a plurality of second input elements appearing when the
input device is fixed in the second position.