USB 2.0 is usually downgradable (not the term I wanted to use but it fits) to 1.1 or whatever, but it can be slower depending of what is being done, I guess. I can use my father 2.0 USB flash drive on my laptop's 1.1 or whatever USB drive but it's very slow. And by slow I mean SLOW. The drive is only 512mb and it can take a half hour or more to transfer the whole thing if full. o_O I don't even want to guess what my 2 gig drive would be like on my laptop.
Seriously, I should get a new laptop.