If you're using a notebook and there's a sudden power outage, no problem: The battery will let you keep on workin'.
Desktop users aren't so lucky, which is why it's essential to plug everything into a battery backup (aka uninterruptible power supply). If the lights go out, you'll still have a few minutes in which to save your work and safely power down the machine.
Best Buy has an APC 550VA Battery Backup System for $39.99 shipped. It includes a total of eight outlets, all of them surge-protected and four powered by the 330-watt battery.
The 550VA promises up to 65 minutes of runtime, depending on the power demands of your hardware. It also has phone/fax/modem and USB ports to keep that gear from getting fried.
APC offers a $75,000 equipment-protection policy, meaning if your gear does get zapped while plugged into the 550VA, the company will reimburse you.
As someone who works at a desktop nearly every day, and who has lost work due to sudden power outages, I consider a battery backup essential equipment. Normally they're a lot pricier, so I'm liking this deal a lot.