I saw David Overton's recent post on the quickest way to shutdown Windows using the keyboard. He recommends using the the following key strokes:
Ctrl+Esc (Windows Key), Right, Right, Right, u
Well that's 5 key strokes - and I can do it in three. All you need to do is make changes to the power settings (as shown in the screenshot above). With this configuration the key combo is:
Ctrl+Esc (Windows Key), Right, Enter
However, this is all irrelevant because with Vista you should never really have to shutdown your machine. We recommend that you use the sleep feature instead which combines the best of both worlds, with a hybrid of standby and hibernate. This means you can resume your activities extremely quickly (productivity friendly) whilst saving as much power as possible (environmentally friendly).