DS7 drew simple recognizable cars and trucks before he was 1yo. He really liked using a Magnadoodle--a magnet "pen" attached to a special board that he'd erase and reuse. It works a lot like a Leapster, though less high tech. It was really attractive to him, more so than crayons.

And, yes, GTness tends to run in families. It's entirely possible that all the kids are GT to some degree.

Kriston