Since RunKeeper discounted it's Pro version (it's free for all of January - I am not affiliated, I promise) a lot of us at work have started competing against each other. I used to run a bit, and it's given me the motivation to start up again. Colleagues who have never ventured off a treadmill are giving it a go. Who can run further? Who can run quicker? Personal bests!

This is my first real notable encounter of peer and game theory, and it's having great results. I can honestly say that I now enjoy working out, thinking about working out, and strangely, analysing my workouts.