Travelling Saleselves
We like to play boardgames at our house. With four kids, it is not to hard to find a quorom. Lately we've been playing the game Elfenland. In Elfenland, each player is an elf that must visit as many cities as possible, by figuring out the best route. Travel is by dragon, elf sled, unicorn and other such magical conveyance.
This game is essentially the travelling salesman problem where the travel costs are dynamic depending upon the terrain and the conveyance. It's a fun game, that we all enjoy (kids aged 9 through 15 and myself). Of course, I usually get beat (like last night, when I came in last).