[pHaestus]

For my purposes PWMing a 12V pump along with 2 120mm fans has been working very well. It's controlled by a MatrixOrbital LCD and linked to a DOW sensor epoxied under the CPU core. Idling/wife using PC for windows/whatever it throttles everything down and the HDDs are the loudest part of the system. Under load everything goes into "full speed ahead" mode and it gets too loud for full time use. If I want, I can turn it down (in the winter when I am running a distributed computing app 24/7) and temperatures suffer a little. If I want, I can run it wide open just to overclock or mess around with it. I am willing to sacrifice a little bit of noise for a lot more flexibility.