When you manipulate a touchpad, your hands shoulb be away from the keyboard's home position. This feature hinders smooth switching between text input and pointer manipulation modes, and is considered one of the primary drawbacks of the touchpad. The proposed ThumbSense input technique aims to solve this problem by sensing users' finger presence on a touchpad. Keys on the keyboard, such as "F" or "J" keys, act both as normal keys as well as mouse buttons according to the perceived user's input status. This technique is implemented by utilizing the sensor feature of the touchpad, and is possible to apply most of currently available notebook computers without requiring new hardware.