BookOfJoe started it for me--working at my computer while walking slowly on a treadmill.
Update: WordsRocked question made me realize that you couldn't see the speed setting on the treadmill. I've been experimenting--0.5 MPH is too slow, 0.8 is a bit fast for me. 0.7 MPH is just about right. You are pretty much walking in place.
Here's the view from behind. I used a Rubbermaid shelf as the base of the desk. I might trim the excess, then again I might not. Turns out it's handy for papers I might need to refer to.
When I ordered the treadmill, I wasn't quite sure what I was going to do to attach the desk. This turns out to work pretty well, using little velcro ties. The bottom rests on the raised speed controls. It's pretty stable. I can adjust the speed with the controls on right (the left hand control is for elevation).
So here you go--Joe's Treadmill Posts
Working and Walking January 31 2005
Walk Don't Run October 12, 2005
Treadmill Hyperspace October 22 2005
Reading and Walking October 23 2005
Treadmill Desk Version 1.0 December 22, 2005
A Treadmill in the OR? January 11, 2006
Laptop Stand for version 2.0 January 22, 2006
Treadmill Dancing February 3, 2006
Working and Walking February 7 2006
Treadmill Desk Version 2.0 February 17, 2006
How to Calibrate A Treadmill February 21, 2006
Treadmill Dancing #2 February 28, 2006
Treadmill Dancing #3 April 10 2006