i posted before about getting a macbook with a 5400 rpm drive for video. (IT ROCKS!) the general concesus was that i would need an external drive anyway, so speed on the macbook doesn't really matter. so now i want to get an exteral drive, but i want a mobile one that is powered off of the firewire. now the only ones i can find are only 5400 rpm, which may not be fast enough for video. is it definately fast enough for video? (i may be working with hd in a few months as well) or are there any reccomended drives that are 7200 rpm with some decent gigabitage?