The exercise-while-desk-jockeying initiative is a valiant idea for a sedentary age, but despite assertions to the contrary by the companies selling gizmos, it's actually harder to concentrate on that spreadsheet when your heart rate has popped your eyeballs out of their sockets and a miasma of your own foul drippings has turned your screen jaundice-color. There is a reason why physicists don't crack superstring theory when in the middle of a series of hundred kilo clean-and-jerks: it's pretty hard to pay attention when you're about to puke out your heart.
Nevertheless, TrekDesk is selling an adjustable desk add-on for your treadmill which they claim will increase concentration and productivity. No, it jolly well won't, but it's a valiant effort, and I like their bouncing chair accessory. It's an exercise ball attached to a seat, and TrekDesk claims it allows you to work on your core muscles while sitting, but upon seeing the pictures, I immediately thought: "Hmm. Bouncing while working does sound like fun." This is Boing Boing, after all.
TrekDesk will be available in Q3 this year, price undetermined.