If I had a job, I'd be all over this one: Treadmill Desk.
What is it? Glad you asked. Far as I can tell, the treadmill desk is the brain child of some scientist bitch at the Mayo Clinic who came up with the idea of slowly walking "on a treadmill while working at a desk built around the treadmill." If that hurts your head to think about, you're not alone. BUT, all you need is
(1) an old used treadmill (2) $39 to build the desk and (3) the desire to change your life.
Evidently, simply walking one-mile-an-hour while surfing the interwebs will burn an extra 100 calories an hour. Who knew?