I may upgrade my MBP with a Hitachi HDD and I'm curious to know if it's possible to use my Western Digital external HDD to act as both the Time Machine drive and also store an Image of the MBP's HDD, using oft recommended freeware like Super Duper or Carbon Copy Cloner? If it is possible, I assume I would have to first set up the drive as the Time Machine drive, since I recall it initially asks for you to format it. Then proceed to placing an Image copy on it. I've never made an Image before; I merely understand it's an exact replica of your HDD. So should the MBP's internal HDD fail one day, I could hook up my WD external and proceed to recover the image on it? (However that is done; hopefully I'll never need to know.) Thank you everyone.