As long as I'm recommending products -- and providing links which, if used, support this blog -- I just bought this expensive stool today, a Swopper. I'm expecting this thing to save me from my bad habit of getting locked into one position while working at the computer for hours on end. Also, I read that fidgeting burns a lot of calories over the course of the day, and I'm thinking the Swopper will promote fidgeting. You can bounce and wobble on it. And of course, with no back, it forces you to use some muscles to sit upright.
Now, one more thing, which I'd like to buy, but haven't bought yet, is a Jesper sit/stand desk. I've seen it in the store. It looks great, and it's motorized with a simple button to raise and lower the desk, so you can make it a standing desk to vary your position. I mentioned this thing the other day in the comments to that post about treadmills in front of desks, and somebody said they wanted more info. So this is the info.
Just some cool stuff that I recommend.
ADDED: I had to get out the receipt to check the name of the stool. I had guessed it was "swobble," but Googling turned up this Urban Dictionary entry. Oops. And here's a very interesting book about the history of the chair. You know, chairs seem so obvious to us, but it's not that natural to sit in chairs. And I'd like to say that I have that last chair pictured on the book cover. You can buy it here. Pic.