UMapper.com has designed a service that allows users to create games on a map using the Microsoft Virtual Earth, Google Earth, Yahoo!, CloudMade, and OpenStreetMap APIs. The USA Trivia Map game embedded below has a satellite map and users are asked to click on the state that they are asked within 15 seconds. The distance from the answer and the time it takes determines the number of points awarded.
The GeoDart feature on UMapper allows the games to be created. Give the game below a try. I found it to be pretty addictive.