I use and recommend the Tripp Lite Isobar surge suppressors, which cost approximately $60.

Audioholics also recommends them: http://www.audioholics.com/techtips/setup/interconnects/bulletproofing.php

I agree with the other posts that a UPS system is not needed. In fact, I have read (but certainly not tested) that some UPS systems may actually degrade performance because of voltage fluctuations.