IMHO, this is clearly a
software problem, so it makes absolutly no sense to
go and swap the computer, much less the HDD. Even if
you do not hear it anymore, the processes will
continue to access the HDD.
Today i decided to swap the original 160G Seagate Barracuda drive against a 500G Western Digital Caviar WD5000SK, which got very good reviews regarding the operating noise. The reason to swap was - of course - not the noise, but the size - i was running out of space on the original drive.
All i can say - the reviews are correct: This drive is basicly noiseless. Even if multiple tasks are gaining access to the HD, you have to put your ear on top of the computer's case to hear anything. No comparism against the noisy Seagate drive.
So guys - if you want a really quiet computer, try to avoid the Seagate drives.
Cheers
Achin
iMac 17" Core Duo Mac OS X (10.4.4) owns also a bunch of PPC Macs