Last night I heard a clicking noise coming from my PowerBook, I think from the right side closer to the front. I immediately turned off my computer. I turned it on a couple of hours ago, checked my S.M.A.R.T. status and it is "Verified" then ran the Hardware test on the install and restore disk and everything passed the test. This came after a day of heavy downloading and installing/removing of applications, my comp also hasn't been shut off for a few days. I have not heard this noise yet today, and am in the middle of backing up the things I need. I'm really hoping my hard drive isn't about to crap out, and don't feel it is. I kind of think maybe it was just a fan, but I'm no expert. Any advice/opinions?