Here one you may know already, but I find really handy. You can create a button on your desktop (In WinXP) to shutdown your PC in one click:-
Begin by right clicking on the Desktop, select New from the Context Menu, then Shortcut. Click on the Browse button and navigate to the file C:\Windows\System32\Shutdown.exe and select it. Click on the Next button, name the shortcut and click Finish. Now you need to right click the new shortcut and choose Properties from the Context Menu. In the box labelled Target, add one of the following letters, depending upon what you want the shortcut to do:
-l (that's the small letter L, standing for Log off)
-s (the small letter S, standing for Shut down)
-r (the small letter R, standing for Restart, or Reboot.)
The command line should then look like this:-
C:\Windows\System32\Shutdown.exe -s
or
C:\Windows\System32\Shutdown.exe -l
or
C:\Windows\System32\Shutdown.exe -r
Hope that's useful to someone.