It's the famous lost scene with Biggs from the original Star Wars! But now that I've seen it I think it's a good Lucas cut it from the film - it's pretty lame stuff:
Also check out this cool black and white video footage of Star Wars auditions:
And now of course you'll need to see the 70s parody of Star Wars: Hardware Wars! You'll laugh you'll cry, you kiss $5 bucks goodbye: