Agreed with the water cooling bit. It's more effective than air cooling regardless of whether or not you are overclocking your system. I made a home build water cooling system several years ago out of an old aluminum heatsink, 1/2" thick lexan, silicon RTV, clear vinyl hose, a 3lb butter tub, submersible aquarium water pump, and an oil cooler from a early 90's 9-series Volvo. It was very very quiet. So quiet, you'd never know it was on if it weren't for the monitor and power LED on the PC.
It worked great for about a year and a half. That is until I went on vacation for a month. When I came back, I discovered someone (I had roommates with kids at the time) had powered my system on without turning on the cooling system first (I never got around to connecting the water pump to the PC power switch). End result was who ever messed with my PC caused the CPU to over heat and warp the lexan, and thus a leak formed at one of the seams. I know it wasn't any of the adults; they knew about the extra steps to turn the system on.
Anywho, I haven't messed with water cooling since. But it's been coming back to my list of things I want to do. Even with monthly cleanings, my PC and my Mac Linux boxes are ever so slowly becoming a bit of a nuisance with the levels of noise their fans make.