The present invention relates to a handheld computerized device with a bit mapped display screen on the front panel, and a touchpad installed in an alternative location. More particularly, the invention relates to a method and graphical user interface that can, for example, enable the user to see the user's finger position and motion from behind the device superimposed upon a virtual keyboard layout on the front panel. This can allow the user to use a touchpad keypad on the back of the device to input keystrokes and mouse actions, and these will be reflected on the display screen on the front of the handheld computerized device as “virtual fingers” or equivalent. The system operates by inputting touchpad data into a software biomechanical and anatomical model of the human hand, optionally supplemented by video or image information to refine this model.