Dasher is an information-efficient text-entry interface, driven by
natural continuous pointing gestures. Dasher is a competitive text-entry
system wherever a full-size keyboard cannot be used - for example,

    * on a palmtop computer;
    * on a wearable computer;
    * when operating a computer one-handed, by joystick, touchscreen,
    * trackball, or mouse;
    * when operating a computer with zero hands (i.e., by head-mouse or
    * by eyetracker).

Dasher is fast, efficient, and easy to learn.

WWW: http://www.inference.phy.cam.ac.uk/dasher/