Firewire400

Firewire traditionally has had a much better sustained transfer rate than USB, even though the theoretical speed is lower. More info is on Wikipedia

I don't think USB 2.0 actually performs at that speed when using External drives. Firewire 400 has always been faster then USB 2.0 for me...

Firewire provides more power also, so you are much less likely to have issues with an external drive requiring a power supply, or one of those stupid Y-cables. This was my main reason for wanting Firewire on my exteral drives...

If you do the Google, you'll find that rated speeds and actual speeds are not always the same.

I prefer firewire to usb for file transfer any day of the week.