Importing with USB 2.0 vs. Firewire 400/800
 

I'm very curious to know which would be the best to import video with into Final Cut: USB 2.0, Firewire 400 or 800. I know that firewire 400 works pretty well, but I was curious to know about USB 2.0, because those drives seem to be cheaper and more available. Has anyone tried using USB 2.0? I'm also looking for cost-efficient things. I know firewire 800 would probably work very well, but its still rather expensive right now. Any thoughts or suggestions are welcome.