Weblog Inspect My Gadget covers three different methods for shutting down your computer remotely. Why might you want to do this?
Think of this scenario; You are lying in bed and just finished watching a movie that you were streaming from a computer downstairs. You want to sleep, but you need to head downstairs to turn the computer off.
All you really need to know is the name of the remote computer on your network and a simple command and you can easily perform the shutdown from the command line, but the post also covers creating remote shutdown shortcuts, other built-in Windows tools, and third-party utilities that can tackle the shutdown process. These methods all require you to be on the same network, so if you're really ambitious you might want to check out how to shutdown Windows with a text message.