The newer Fujitsu drives (I recently added a 30/40GB (?) drive to someone's Empeg for them) are quieter than the fans in my docks. Very very quiet.

Many drives also implement the "Acoustic feature set", which permits the O/S to set the tradeoff point between noise and seek performance. This can make a HUGE difference on desktop drives. Not so sure about laptop drives, or whether any of them actually implement it. "hdparm -I" will tell about those that do implement it, and "hdparm -Annn" is used to select the desired sound level (drive remembers it permanently once set).

Cheers