I have a 500GB external HD that I've used with my old MBP and now I'm questioning whats the best scheme for backing up my MBP HD. I was thinking: Partition 1: Bootable OS X (with nothing, like factory install), to use in troubleshooting if my MBP dies. Partition 2: Use Time Machine or CCC to backup all files I don't know the pros or cons of using TM vs. CCC. Some help would be appreciated. If I did decide to create a bootable partition, what size would it need to be (blank OS X Lion). Thanks.