A UPS is going to be expensive due to the current draw involved, and it will be only good for a short time unless you get a really big battery. Some folks do it, but I'd hardly consider it a necessity. I do think that some good surge protection is smart, though. I got a Belkin unit on significant discount a while back (list price is absurdly overpriced), but there are plenty of other options out there from folks like Tripp-Lite, Panamax, or Brick Wall.