He gets around ...

Cooper now sits up and even crawls, to a point. Actually, it's a very bizarre sort of crawling that's difficult to explain. He gets up on his hands -- which is fairly basic "baby," really -- but he also gets up on tiptoes, instead of his knees.

It's sort of like watching Spider-Man, only on the floor instead of on the wall. Very weird. We'll try to post video later on, so you can at least believe us.