Hey Stephen F--
Jack said he thinks you use a variable-height desk--i.e., one that you can easily move to a standing or sitting position. I'm thinking of buying one such, would appreciate any comments, recommendations, un-recommendations, etc. If anybody else has experience with such things, all comments are welcome.
And if you DON'T use such a thing, perhaps you should look into it/them. If you're at a desk for many hours a day, standing for at least a portion of that time is supposed to be much better for you in general and your back in particular than sitting.