Long before he was the lead-singer of the self-appointed greatest band in the world, Jack Black was a pint-sized pitch-man for Atari. Check it out:
The comments are worth sticking around for too. They range from, "He's so adorable… and FRIGGIN' ASS-KICKING AND AWESOME!" to "The guy is a greasy fat unfunny turdgargler." However, we found, "he looks the same, but less fat lol," to be the most thoughtful. less fat lol, indeed.
Don't forget, you can also see young JB in The Neverending Story III.
http://www.jackblack.net/gallery/albums/userpics/10002/uvs050706-016.JPG