A dead pedal is a fake pedal on the left side where you can rest your foot when it's not on the clutch.
It can provide good firm flat place to put your foot, which is extremely useful in hard corning to brace yourself.
Dead pedals are nice because they tend to be a harder and flatter(sp?) spot to put your foot than just a carpeted bubble on the floor.
If they put a dead pedal in, it also is more likely that it's better placed for more comfort and support.
Though, in my Acura TL, the dead pedal is probably a full 3-4 inches behind the rest of the pedals and makes the driving position a bit awkward.
Oh and dead pedals look nice too...
