Automatic shut down with Handbrake!
If you don't like to leave your computer running all night but want to take advantage of this time where your processor is 100% idle to re-encode video, a great feature in Handbrake is for you. It also lets you do a whole lot more. You can choose specifically what you want Handbrake to do after the encode is over (sleep or shut down your computer). It will even let you switch to a Growl notification instead of the usual "Put that cocktail down.". It is located in the Handbrake preferences, under "When Done".