i have a 2.16/black intel core duo 2 macbook/4gb ram (3.3)... i've had the mb for about two years now and i've never really looked into ways of keeping it at peek performance (like i used to do with windows.. defragmenter etc etc). this is due to the fact that the macbook is still as responsive as it was the first day i got it, and it has every program you can think of (final cut, logic studio, imovie, photoshop, live, etc etc). i've spent a pretty high amount on software and i'm not complaining... HOWEVER... i wanted to know if i should do a yearly or monthly checkup, and run a certain utility to keep the macbook at peek performance and speed? any software out there that's worth buying that cleans unused files and clears up hd space or perhaps a disk defragmenter type utility? or any other ways of keeping it at its peek? i would truly appreciate the suggestions.