Geeks and Weight-loss?

WideLoad asks: "A decade or so spent at a desk in the IT industry has left me with a physique that can best be described as looking like a half melted wax Buddha figurine. It seems to be a common problem for those of us whose career and hobby tends to promote a sendentary lifestyle. With the holiday gorging season upon us and in need of inspiration and/or motivation I thought I'd ask: what are other geeks doing about their health?"