Normally, when you reboot a PC, you select "Shut Down" under the Start menu, and well, shut down. What happens then is known as a "cold boot": the PC briefly powers off, then restarts, and then the basic BIOS software loads, followed by Windows.

You may know that under Windows XP, holding down "Shift" while clicking through the shutdown menu will place your system in hibernate or standby, depending on whether the button is depressed or not. In Windows XP as well as Vista, this guy discovered that holding down "Shift" while invoking the command to restart will cold boot your PC.

All in all, it saves about 30 seconds.

There is a caveat or two: on some computers (especially laptops, like the ThinkPad I'm currently using) the BIOS needs to load, or else the hard drive containing Windows won't be found. Simply powering off should fix things, however, in case this occurs.

Found via Digg.