....and I just Googled footrest instead of footstool and found it. The Webble. http://www.thewebble.com/buy.html

If you used one of those and used an exercise ball as a desk chair, you'd really get a workout! (Or fall over a lot, one or the other.)

That thing looks great. Did you get one?

Specklet, a friend and very fit/knowledgeable personal trainer of mine would often recommend resting my feet on a basketball or medicine ball whilst sitting on a yoga ball as a more advanced balance/core exercise. Not for the faint of heart or weak of balance, for sure. I doubt I could actually type or work accurately while doing it.

My massage therapist recently told me that he sees a lot of desk jockeys with worse back and shoulder trouble than normal these days, and it's often because they sit on a yoga ball at work, but don't actually sit on it properly, and that can do more harm than good. The ball needs to be inflated to the point where it's quite firm, and then you need to sit to the front of it / lean forward a bit so that you don't slouch.

Probably fall over a lot, Specklet. ;)

No, I haven't gotten one yet, I'm thinking it over. $150 is a lot and could also buy a Chumby One. I'm debating.