Another option to reduce drive noise is to use the Hitachi Feature Tool
. This software is on a bootable CD or bootable floppy disk, and allows you to change the acoustic managment settings of most IDE/SATA hard drives (not just Hitachi - I've successfully used it on Western Digitals and Maxtors).
If you set the acoustic management all the way to maximum, it can make even Maxtors quiet.
The drawback of acoustic managment is that is increases the average seek time of the drive, slowing file access.