I was reading an article in the Jan 2010 issue of Macworld or Maclife I can't remember which one but anyway they did a test looking at portable hard drives and the one they recomended was the 500 GB WB Passport Studio. It performed best of all the different models they used for their study. That's the one I will be purchasing for my MBP. I'm going to wait until after the holidays hoping someone in my family will buy me a Best Buy gift card.