lately i've been getting into more and more video editing, and have heard alot about the use of a scratch disk for editing. I have a 17" powerbook and the internal drive is way too small and slow for me and i need help with external firewire drives. I really want to use the firewire 800 port on my system but i'm beginning to wonder whether it is worth it or not. so i'm asking all you video experts out there whether it is worth the extra money to get a firewire 800 drive (keep in mind i am a student, low cost is a must, i'm buying a drive instead of one of my textbooks ) will I notice much real world speed difference when using the drive as a scratch disk? also, is it cheaper to buy an enclosure or a drive with a hd already inside? and is ebay even worth my time to look through on this one (i'm in canada btw when you are thinking of stores)? i'm looking for at least 120 GB i think, 80 just seems too small anyway, anything and everything will help me out, and i look forward to some good replies as I know i can get them here p.s. final cut on a 17" laptop is oh so very sweeeeeet!