I'm shopping for a 500 gb external hard drive, to use primarily for backup, storage (and playback) of media. I'm not planning on using it as a scratchpad for photoshop or anything like that, but I don't want to wait an hour every time I backup my 160 gig MBP either. I've basically decided on a Western Digital My Book. BestBuy has the standard model, USB only, on sale for $130. The Pro model that has firewire 800 goes for $195 at the cheapest. How much gain in speed would FW give, and is it worth the extra price? I'm also considering getting the network (gigabit ethernet) version, but I have no idea where it fits in in terms of speed.