Screen scanner utility for GNU/Linux which allows the user to control the mouse pointer by using the keyboard or by producing sounds which are captured by a microphone.
Packages for Ubuntu may be found here: https://launchpad.net/~shoden/+archive/nadir
eye-pointer is a set of libraries and programs for computer vision, especially for locating the spot on the screen you're looking at. The ultimate goal is to incorporate that facility into a pointer (mouse) driver.