Saw this on a mountain biking forum. The winter olympic biathlon combines cross country skiing with rifle marksmanship. These guys replaced the skiing with mountain bikes and rifles with bb guns. Marksmanship scoring is simple. Shoot until you pop the balloon and then pedal another lap.
http://www.ratrodbikes.com/forum/viewtopic.php?f=59&t=78520&p=760311#p760311
http://www.ratrodbikes.com/forum/viewtopic.php?f=59&t=78520&p=760311#p760311
