After (nearly) filling up the 'stock' 120GB Hard Disk on my late '07 Mac Book Pro, I bit the bullet and ordered a 320GB WD Scorpio (£85 GB Pounds). Fitted it this morning, using the guide from IFixit - http://www.ifixit.com/Guide/Mac/MacBook-Pro-15-Inch-Core-2-Duo/Hard-Drive-Replacement/115/10/ The only tools needed were a T6 Torx Driver and a 00 Phillips, I also used a plastic spreader to help pop the case open. I got both 'drivers from my local "Maplin" (UK equivalent of Radio Shack I guess!) I was surprised at how easy the whole task was, considering you have to open up the MBP case, there were a total of 20 screws to remove, and two bits of adhesive tape. Fitting the actual disk took 40 minutes (I was taking my time); once the new disk was in, it's a simple matter of booting from the Leopard DVD, and using Disk Utility to partition the 'new' disk - then, I simply restored from my last Time Machine backup (on an external USB disk). That step took two hours. When rebooting, Spotlight has to reindex itself (which slows things down a little) and launching Mail for the first time causes Mail to reimport all existing emails (took about two minutes for some 3,500 mails!) The reason for posting this is just if there's anyone else considering the upgrade of their Mac Book Pro hard disk, but concerned about the complexity of the task, then *don't be* it is quite simple, and provided you take your time (especially when popping-off the top case, and be careful not to lose any screws!) you will be good to go in a couple of hours.