I remember somthing deep down in a bios setting somewhere something about having the option to "restart computer on lost power" or something like that. It's there I guess to make sure that is your machine is a server and power is lost it will reboot when power is restored, allowing any process running as a service to "get back into business" even if nobody is there to log in. Good for servers and such. My advice would be to plug the cpu and monitor into a UPS system and plug non-essentials into a good surge supressor strip. Just use the computer power button to power it off. Then you could throw the switch on the strip and turn off speakers, etc at once. Be careful using this method on printers - if the print head isn't seated you may dry out your cartrdge prematurely. Use the power button on printers to ensure the print head is parked. Throwing the switch on a plain power strip is no protection from surges, etc while the computer is on, anyway. And nearby lightning strikes can arc across the switch and fry stuff even if the power switch is in the "off" position. Pulling the plug from the wall is a better option as far as lighning protection goes. But remember, anything running into your computer that isn't running through a good surge protector can fry your system; modems are a primary culprit... network cables from hubs and cable modems are, too... cable tv coax for TV tuner cards are often overlooked as well. Even if everything else is running through a good UPS battery back up device (ACP is what I use, other brands are decent as well, but beware cheepies), if, for instance, the power brick for your speakers is left unprotected, lightning could get in through the wire running to the sound card and get your system that way. I know I'm paranoid, but after having a system fried a long time ago through a modem's phone line, I've been using UPS's and total surge protection for 8 years and I've yet to lose another system that way. Now dropping a screwdriver into a running system, getting p*ssed and yanking a stubborn IDE cable loose, or accidentally plugging the power cord for a 9 volt AC answering machine instead of the 9 volt DC power connector into an external hard drive... now that's another story!
Hope I've helped,
Steve