Check this video out. Somebody has dubbed Arnold's lines onto footage of Vader. It actually works and is funny! http://www.youtube.com/watch?v=xh3Wveg4DMk
Strangely enough, Arnold's voice doesn't sound that deep when heard out of context. GREAT payoff at the end! Sincerely, Bill
There are some other ones on there, using Gunnery Sergeant Hartman, Samuel L. Jackson, and Tommy Wiseau.