Some time ago I saw software running on either a Mac or a Linux desktop which enabled full keyboard control of mouse-centric GUIs. The user could press a hotkey which divides the screen into sections, and the user would narrow down the section of the screen using the keyboard. By bisecting the X and Y coordinates on the screen the user could easily click on any place on the screen.
I am looking for such software for either Linux or Mac OS-X, as I use both operating systems.
I am not referring to Mouse Keys, in which the user must push the mouse in the required direction with the keyboard.