The Traveling Santa Problem was contest hosted on Kaggle.com in December 2012. Given a list of all the cities where Santa needs to drop off his packages, the goal was to provide two routes for Santa such that he visits all the cities at least once on each route, but so that no two connections between cities are shared between the two routes (Santa likes to see some new scenery each year).
This was my first contest on Kaggle. I didn't do very well in the competition, but I had a fun time thinking about how to optimize the route. I tried implementing a basic simulated annealing approach, which was an algorithm previously unfamiliar to me. It wasn't enough to take 1st prize (or anywhere close for that matter), but it did achieve quite a bit better performance than the nearest-neighbor approach.