Control-Alt-Backspace combo in Ubuntu

This is based on query from some of my Linux friends. Linux has a standard way to 'kill' the X-server, that is the GUI, in case the GUI hangs (Yessss, in Linux too the GUI hangs sometimes when doing crappy things like heavy animation or special effect stuffs, or java stuffs!!). The 'kill' is done using the key combination  'ctrl+alt+backspace'. However, Ubuntu disables this key-combo feature by default (cannot fathom the logic for this!!). However, this can be easily restored.

To enable this key combo in Karmic Koala (Ubuntu 9.10) is pretty simple, just go to:

System –> Preferences –> Keyboard –> Layouts (Tab) –> Layout Options –>
             Key sequence to kill the X server 

and (Tick) Control + Alt + Backspace.