I remembered reading about this one time, but I totally forgot until now.
Ladies and gents, I am going to make a treadmill desk. I found a $25 manual treadmill on Craigslist. I will probably pick it up tomorrow.
See where it levels off? That is where the desk portion will be. Awesomesauce! I can now do two of my favorite things: walk/run while browsing the internet or programming!