Is there a Control-Alt-Delete key

[Habbam]

My Ubuntu crashed as soon as I started Firefox, and when I logged back in all I get is a dark screen with the word "Ubuntu".

[OllyDBG]

No but u have Ctrl-Alt-F1

[PerfectReign]

Yes, that downgrades you to the command line.

You might be able to do some items there.

[wilee-nilee]

For a better way to shut down.
http://en.wikipedia.org/wiki/Reisub
if you sub the b at the end with a o it is off not reboot.

[Habbam]

So what do you all do if the machine stops responding?