Child always on the go - what are your thoughts?

It sounds like it's in the spectrum of normal.. maybe a little on the hyperactive side. In your shoes, however, I'd be equally concerned (my daughter is 3 1/2 and isn't as hyper as you're describing, but many of her boy-friends are doing exactly what you're describing your son does.) You can't hurt anything by talking to his doctor again.. but what's your biggest concern/fear?