Upgraded my new MacBooks HDD last night to a Seagate Momentus 500GB 7200RPM. The whole process of changing the HDD was easy up until you have to take the mounting screws out of the old HDD to put in the new HDD, which requires a special star screwdriver (which I did not have one small enough!) to get them out. I had to resort to using pilers to get them out, which was not ideal but I managed to do it without damaging them. Apple should state in the manual what tools are needed before you begin a job as I found myself sitting there with the eight screw rear panel off, the bracket off and the old HDD in my hand. I managed to fit the mounting screws to the new HDD and place the new HDD back into my MacBook. The HDD assembly within the Macbook is well designed in regards of the mounting screws that slot into the sides can never loosen and come out because they are held in place in a manor where the screws cannot escape. Just wish they was fitted with a normal screw thread! Once I re-assembled the MacBook, I powered up and re-installed Snow Leopard, which took 35 minutes. The faster HDD has defiantly made a difference to loading times, Safari is instant with once bounce if your lucky and iTunes about one and a half bounces. So anyone who is going to change there HDD just make sure you get the right tools before you begin.