Modern Language Association (MLA): "dirty power." The Free On-line Dictionary of Computing. Denis Howe. 09 Jul. 2007. Dictionary.com.

Dirty Power --
Electrical mains voltage that is unfriendly to the delicate innards of computers. Spikes, drop-outs, average voltage significantly higher or lower than nominal, or just plain noise can all cause problems of varying subtlety and severity (these are collectively known as power hits)."

So, we are given to understand that dirty power is to the computer what cigarettes are to us, in that they shorten life and make us run like crap.

OK, so what's this got to do with you? Only this: the Bay area received a pretty hard hit with Hurricane Katrina, and while Coast Electric, Mississippi Power, and other power companies are doing their best to get things back on track, the power coming out of your outlets in your home or office is probably far from optimal. This means that the life of your computer or laptop may be significantly shortened due to dirty power. In home environments, this can be painful, especially if those digital photos of your Aunt Bessie get lost forever because your hard drive failed, but in business environments it can be ruinous. [edit: GCITS found the power in Atlanta, GA, to be almost as bad as the power in the Bay area, with frequent brownouts, blackouts, and rolling gray-outs, whatever those are supposed to be, so let's not knock MS Power and Coast Electric too hard.]

GCITS recommends that you place your mission critical computer systems (especially your servers!!!) on battery backup, but particularly battery backups with Automatic Voltage Regulation (the terminology may vary from vendor to vendor). AVR takes the "110VAC" from your outlet, changes it to a DC voltage, then changes it back to AC again. Only this time, the 110VAC waveform is perfect in every way. This will make your computer last a long long time, and run better, too. And when you do encounter a blackout or brownout, the battery backup will help your computer either ride out the power outage (depending on the length of the outage and the size of your UPS) or at least shut down gently.

At the very very least you should have your computer equipment plugged into a power strip that protects (and guarantees) against lightning strikes and power surges. If you use DSL or a phone line, you should have that protected against lightning strikes as well.