Average electricity cost

Alright, with all those talk about XBOX360 eating alot of electricity got me wondering, I'm on my computer alot, about 3-5hours a day, with a 19' inch monitor, around how much would that cost monthly? Just wondering.

Bullpies. You try running a modern PC on a 150W power supply and see how far you get. Prescott-core P4s consume >100W on their own, and high-powered graphics cards aren't far behind. The motherboards suck up quite a bit too - some north bridges require active cooling, plus you have at least four or more fans churning away in the case (at least another 25W in fans alone). And the PSUs aren't generally the most efficient devices either. You could call 200W average a few years ago, but not now. Things are getting under control again, what with AMD's cool-n-quiet CPUs, and Intel's forthcoming plans to reduce power consumption (basing their next generation of CPUs on the same design philosophies as the laptop-friendly Pentium-M), but current stuff is still very thirsty.