I searched and couldnt find the exact answer, so i'll ask you guys.. Whats the best external HDD for TM? How big should it be for this purpose? Specifically, i would love to buy one that doesnt require an external power source, because i will be using it with the laptop, on the road, a lot. Which is better for this? FW800 or USB? Whats the disadvantages of not having an external power source? Slower read/write speeds..etc? Thanks everyone! Love the community!