It sounds like he might be a kinesthetic learner. They learn best by moving while learning. If you've ever seen "Akeelah and the Bee," the movie about the girl who becomes a spelling bee champion, you have a good idea what kinesthestic learners might look like. Movement helps their brains to work better.

The other possibility that comes to mind is that he's just THAT smart, so he needs to be doing two things at once or he'd be bored.

Kriston