If you have a 60 GB PS3, it's probably louder now than when it was new. The problem is Sony used a cheap heat sink compound which remelts each time the temperature rises. With the clamping pressure of the heat sink to the CPU it migrates out from between them.

I took my PS3 apart, cleaned all the old compound out with ArctiClean, and then used a little ArcticSilver to replace it. After the AS cured, the fan hardly runs at all anymore, and when it does it is at a lower speed than before.

Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris