Hi,
As far as I know, there's nothing in Vista to do this.
You can choose to turn off the display and the hard drive :
Control Panel>PowerOptions> Change plan Settings>Change Advanced Power Settings
there is a gadget, from here:
Download AutoShutdown Vista Gadget 1.4.1 - Vista gadget that will you access to an automatic shutdown utility on your desktop or sidebar - Softpedia
Hope that helps
SIW2