As mentioned earlier I like to watch TV shows via torrent files. Often times I will start the torrent client and let it run thru the night. But at the same time, I don't like the idea of my Powerbook working all night. This is where iWillQuit comes in.
iWillQuit does just as you expect. You can choose to sleep, shut down, restart, or log out after a specific amount of time. So go to sleep and know that in a few more hours you Mac will join you in dreamland.