This suggestion comes from experience: I have a very noisy MacBook5,2, and use Macs Fan Control to slow the fan to a bearable level. I believe a Core 2 Duo with a clean radiator doesn't neet to run its fan 4500rpm at 61 degrees.
However, I am not sure at what temperature does the CPU lower its frequency, and I think it would be a good information to have when setting cooling profiles:
One such profile would be "silent", putting quiet-ness before any other consideration.
Another would try to maintain CPU frequency as high as possible while only speeding the fan as needed.