New York City as a Risk board
No jokes please about New York always having an element of Risk. A group of hackers (the fun kind, not the steal your credit card kind) have developed a citywide game of Risk based on Foursquare check-ins in New York. Players first swear their allegiance to one of the five boroughs (why do I get the feeling that Brooklyn is totally going to win? This has Brooklyn written all over it) and then check in as they go around the city. Traveling constitutes an invasion. An algorithm determines a winner for each little part of the city depending on how many people checked in from a given borough. There are about 100 players currently.