Shutdown Xpert lets you force a shutdown or reboot or set your PC to shut
down automatically after a user-defined delay. The main advantage of using
such an application is that you will no longer need to wait until your
computer completes a shutdown or reboot. This would allow you to get on with
other things with the knowledge that your computer will definitely shutdown /
reboot and will not hang due to open applications demanding some input from
the user before a shutdown or reboot could complete. (in System Utilities)