I have a watercooling system in my PC now:
Swiftech MCP655 pump
Swiftech Apogee GT water block
1 x Black Ice GTX 120mm radiator
1X Black Ice Extreme 120mm radiator
Swiftech MCW60 waterblock (still need a HSI heatsink so I can use it with my 8800 GTS)
My Athlon 64 X2 4600+ gets about 35 idle, at 2.8GHZ and 1.5V
when both cores are at 100% load for hours, it gets to about 50
I want to upgrade to an Agena (quad core) when they come out, depending on prices.