Hi fellow MacRumors' users. I'm debating purchasing an external HD. I have a MacBook Pro Core Duo and am debating between a FireWire and USB 2.0 external. Which one will be faster in real-world use? I know I can use either for Time Machine. Will they both work for booting of the external if I want to Carbon Copy and boot my disk image on to another machine, or do I need to use a FireWire drive? Thanks for your time.