I am in the market for a new external hard drive to use with Time Machine since my last one just bit the dust. I'm looking for a 1 TB, and am noticing there are USB 2.0 drives like Western Digital that are pretty cheap, but most that have up to Firewire 800 are quite a bit more expensive. Not surprising obviously, but my question is, does it really matter when it's just being used for Time Machine? The speed doesn't really matter as far as I can tell other than if it's a loud drive and becomes annoying each hour as it backs up a little more data. What do you guys think?