I always liked the Ctrl+Alt+Backspace combination to kill the desktop environment in Linux, for different reasons: because the graphical interface just freezes or maybe because I reconfigured the desktop environment and it is a fast way to restart the X server. But since 10.04, Ubuntu has disabled this key combination. Luckily for us (or may I say for me perhaps), enabling it again is really simple.

With the text editor of your choice, open the file /etc/default/keyboard and change the following option.

XKBOPTIONS="terminate:ctrl_alt_bksp"

Enjoy!