DANNY365  I have recently purchased iDefrag to help my PowerBook 12'' *60 GB* disk survive after several years of moderate use. The disk was about half full, and I suspected it caused some slowing down. The app. worked fine for me (nothing special, 2 hour job after booting from the disk the supplied app. created.) I do sense some quickening, not dramatic, though. I would still buy the app. not to take the risk of a fragmented disk.  
(Version 1.6.8)