1. A portable processing device comprising: a detachable handset unit sized for handheld grasping and including a central processor and a plurality of first circuits, said processor controlling the operation of said first circuits, and said first circuits including at least one interface selected from the group consisting of a video interface, a keyboard interface, a communication interface, a pen-input interface, an audio interface or combinations thereof; a portable docking display unit dimensioned substantially larger than said detachable handset unit, said portable docking display unit including a first display and a plurality of second circuits, said plurality of second circuits not including a central processor and including at least one interface selected from the group consisting of a video interface, a keyboard interface, a communication interface, a pen-input interface, an audio interface or combinations thereof, and wherein said central processor controls the operation of at least one of said second circuits and said first display when said detachable handset unit is docked with said docking display unit.