Since I'm into ergonomics a number of friends have sent me this link on the hamster wheel desk. I think it's very funny and I thought I'd share with everyone here.
In my opinion however, this is not very ergonomic. Studies have shown that holding onto the handle bars of a treadmill forces your upper body to be very static and not dynamic as you normally would when walking. This influences the dynamics of your walking in such a way that isn't natural and puts your posture in a position that you don't want. That can be applied to typing while you are walking as well. So while I think this is hilarious and I would love to actually have one I wouldn't recommend using one for long periods of time. In fact just get up and take a walk every 50 minutes for 10 minutes and you will be way better off. Also use a standing desk.