Dr. Levine told us two years ago that we are designed to move, not sit. That's why he has his computer mounted on a treadmill. Then Steelcase came out with an integrated treadmill workstation, but it is too expensive and just sucks more power.
The smart kids at MIT have a better idea; they converted an exercise bike to charge a battery, that generates more than enough juice to run their notebook computer. As the bike's instructions note, if you have trouble "squeezing in that daily exercise," you can now "multitask with no problem--[you can] bike while you work!" ::MIT News via ::Splurch