I just installed snow leopard last night (Clean install). I left my macbook on the entire night to let it run any utilities it needed, since I loaded it with new software (Office 2008, iLife '09) and my media (Music, Photos). I've noticed for the past 2 hours of using it today, the Hard drive has been making a weird noise, which is hard to describe. It's a fast paced sound, with very quick 1/2 second noises. It's not a clicking or anything, rather, it's the sound the hard drive makes when accessing something (the pattern gets broken up when you actually do open a program, and the disk accesses a program to load). I'm wondering of maybe my mac is indexing something? Or if there is something bigger wrong?