When I contacted Nick's breeder regarding is behavor problems, she actually suggested putting him on a treadmill to "expell his nervous energy"!! I though it was a wonderful idea - but I don't own a treadmil.
I could buy a human-sized one for the price of this one, though! We are not getting a treadmill - we are going to obedience classes, instead.
If it was cheaper, I would actually consider owning one.