UPS.. Uninteruptable Power Supply...
These things have saved my ASS in the past... Basically it is a power strip/surge protector that has a built in battery. When you lose power it will provide up to 5-15 minutes power to your PC... plus most come with software to save all your files and shut down your PC.. I went with APC as I have had one in the past..
If you lose power, your stuff will be safe.. I think this type of product along with a hard drive back up are necessary for every dedicated computer user!