Which is the most quiet Hard drive?

I am on a quest to turn my old Northwood P4 3.0Ghz PC into a silent PC. After $250 worth of parts, it is coming close to absolute silent. I have a fanless power supply as

well as a fanless heatsink. CPU idles at 34C and shoots to 50C under 100% load. I can accept that as it is only 8C higher than using my old fan/heatsink combo.
Now, the only noisy part in the computer is my raptor hard drive spinning at 10,000 rpm. Right at bootup, I can hear it's whizzing hum. My question is: what is the most quiet

hard drive out there? I heard the samsung brand has some quiet ones. Any suggestions?