A few weeks ago, I pulled the trigger on a purchase that I've been thinking about for years: A treadmill desk. Stephen O'Grady helped seal the deal with his post on his treadmill desk.
Setup is actually pretty easy, as long as you have a second set of hands. It took about an hour – including the time required to clear the space – and it was up and ready to go.
Right now I'm walking at a clip of about .7 miles per hour and it's perfectly comfortable. I've been adjusting to standing while working for a while, so it's not a huge shock to the system to work standing rather than sitting – it's the constant motion of walking that's going to take some adjustment.
With any luck, this will help propel me to being a lot more active. If you're a treadmill desker, any tips would be welcome!