The Team monitor
If some application crashed badly and maybe won't disappear from Deskbar's running application list, press CTRL ALT DEL to invoke the Team monitor. Here you can select an entry and kill a misbehaving app.
A neat way to quickly get rid of an app hanging in the Deskbar is the Vulcan Death Grip.
Hold SHIFT CTRL ALT and click on the offending entry in the Deskbar. Poof!