[darkstar999]

I've had less back pain since I started standing at work, and I've heard many similar stories.

You can also "walk in place" to get the heart rate up. Good luck doing that in a chair.

[wlscaudill]

Lots of swaying helps keep everything loose as well as keeping focused on using the leg muscles to support yourself instead of relaxing and letting the cartilage do all the work which is the only real concern I've come across for a standing desk.