A system for receiving, storing, and displaying biometric input has a touchpad and a digitizer. The digitizer comprises a substantially transparent touch activatable overlay placed over the touchscreen and a plurality of sensors supported by the overlay to detect input to the overlay. The digitizer includes a data outlet for transferring the detected input as overlay data so the touchpad can visually display the detected input on its touchscreen. The digitizer has sufficient sensors that the overlay data contains more information than the touchpad data would if the touchscreen were contacted directly without the digitizer present.