I'm posting this as an FYI for those who are considering upgrading the hard drive in their MacBooks to a 7200 RPM hard drive. I installed a Seagate 200GB 7200 RPM hard drive in my MacBook last night. Today, I finally noticed that it causes both sides of the front palm areas (beside the touch pad) to vibrate slightly. I never noticed this before with the original 5400 RPM drive which was also a Seagate. It's very slight, but definitely noticeable.