I built the same treadmill desk that Maxwell made. That thread is probably gone because this forum likes to eat threads older than 2 years (I propose we let threads live for 5 years, as I ran a forum for long time and it ran fine without much culling).
The desk is an IKEA FREDRIK (the skinny one):
http://www.ikea.com/us/en/catalog/products/00115992/The treadmill is a Horizon Evolve:
http://www.amazon.com/Horizon-Fitness-H ... 243&sr=8-2I won't go into detail like Max did, but you basically take that desk, remove one of the shelves on top, raise the big desk portion up higher so it's taller than the treadmill, and there you go. If you want to use another treadmill that is not compact, you can consider the full IKEA FREDRIK:
http://www.ikea.com/us/en/catalog/products/60115989/They come in a birch color too. Look on the site.
I lost a lot of weight due to that treadmill. However now that I've gone back to working at an office, I sit most of the day and gained back some fat. I don't stand all day at the treadmill though, when I'm at home. I have my tv and couched hooked up to sit when my joints are tired (it's not tiring to be on a treadmill for hours, but it hurts my joints, and I'm 31, so not really old). Your situation may not allow the set up I have, so you might just invest in a comfy stool to set on the treadmill should you get tired of walking or standing. Bottom line: the treadmill desk is great, and I'd use it at work if I didn't share an office with others.
I find it funny that there are Skyrim workouts, and workouts for other games, to get people off the couch/chair and get exercise. I just use the treadmill desk so gaming == healthy!
I don't have much more info, but I can answer curiosities. Good luck!