In one general aspect, a computing device can include a display, a touchpad configured for moving a cursor on the display, and a keyboard for inputting input into the computing device. The computing device also can include a scratch region mutually exclusive from the touchpad and the keyboard. The scratch region can be configured to receive input to the computing device based on contact with the scratch region. An interaction detection module can be configured to detect an interaction with the scratch region, and configured to generate an indicator of the interaction. The computing device can also include a scratch region analyzer configured to define an alphanumeric character based on the indicator of the interaction with the scratch region.