If you are in the "small number" of people who are seeing hard drive stalls since Snow Leopard and that Unibody MacBook Firmware update that allowed 3Gbs SATA, Apple finally has an answer - in the form of a "Performance Update 1.0." Though, it only affects a small number of users, anyone with a recent MacBook of any kind running Leopard or Snow Leopard should download this update.
FWIW, I'm in the "small number of customers group" who've had the spins. It is a 108K download. Get it now - or simply do a Software Update.
Update: I am on the other side of the update. No spins and long lostdare I saySnappiness™
Details below.