I'm running a Kestrel III CPU fan and it cools fine. But at high temps it's running flat out at 5,200 rpms or so and it's loud as a bastard. I need a socket 939 CPU fan and cooler that will run quiet, cool not require exotic hardware. Don't want water, but anythng else I'm game for.
If you don't stand for something, you'll fall for anything.
I use a zalman "fan mate 1" rpm adjuster, and run my Intel heatsink fan at about 2500 rpms. It increases anyway when under load, but at the lower setting, it's still quieter. They sell for about $5 at Fry's. Some online dealers may only carry the "fan mate 2" for a few dollars more. When adjusting, there's no required setting. Just turn down the rpms until your ears are more comfortable. I also switched to a sparkle 300w power supply with the 12cm side fan, and it's very quiet, and reduced my cpu temps by at least 5 degrees celcius. I highly recommend it.