Hey All, I'm a recent switch to Mac, I've been a PC builder for years but as a professional illustrator it was only a matter of time before i heard the Apple Siren Call. That being said, I have a late 2008 MBP 2.6Ghz with 4GB RAM, 512Mb GeForce 8600M GT and 200GB 7200rpm HDD- I got it new the day the next generation was announced (at an awesome discount worth jumping at) It has steadily been running progressively slower, getting noticeably worse in the last couple weeks despite the fact i haven't really loaded on any new signifigant files. It is used primarily to run Illustrator, Indesign and especially Photoshop (CS3). The biggest noticable difference is when watching any video, which will steadily slow down and become choppy, or when working on the files. Being a PC user, my first thought would have been to find a Mac equivalent utility to defragment the harddrive, but was told by a Mac associate that macs do not require defraging, that the OS has a constant-stream refraging directive built in. I'm not sure what to think, being both a PC and Mac enthusiast- it seems like having a feature like that built into OSX 10.5.5 would be appropriate for apple's claims of a cleaner-running OS, but the weekly-defragging PC side of me is skeptical. What could be causing this slow down? Is there such a thing as defragmentation in OSX? Any ideas would prove helpful!