Couple thoughts:

empeg enclosure should = quiet?

www.tomshardware.com has discussed noise before, but probably not "all the time". Worth a look in the notebook drive comparisons under their "storage" reviews.

I've had limited experience on Fuji's vs. others - my Compaq X1050 notebook. I swapped the 40GB Fujitsu 4200 RPM drive for a 50GB Hitachi 7200 RPM. The Fujitsu was MUCH quieter at any time (Thankfully I don't care, and the performance upgrade was all I could ask for).

I haven't seen it through the O/S before, but I do remember old IBM drives (I think there are others) that had a quiet mode you could set through commands used when booting from their special floppy disk. I'm pretty sure those settings were hard set and stayed with the drive, even if you moved it from one PC to another.