not really a fan of Kutcher or his work either but he does look a lot like 70s steve and off the top of my head can't think of anyone better
I vote for Noah Wyle, afterall Steve himself gave the guy a thumbs up at the 1999 Macworld keynote when he said 'he's a better Steve then I am.'
----------
Good call, never thought of Jack Black, but that would be excellent!
I could see Jack coming up with an idea to build a box that would imitate the different tones of various coins in a phone booth to get free phone calls.