I recently bought a 160gig 7K250 SATA for a new system. Was concerned about the noise but it doesn't make any meows or much of anything else. Whew!
I have it installed in a Zalman ZM-2HC1 drive inclosure in an Antec Sonata case.
But the case is still open and its been running off and on for a couple of days now with no apparent problems or noise - I wonder why?
Getting it installed as the single (boot) drive in my Asus k8v was an adventure but all's well now.