Odyssey of the Mind (often called OotM and OM, but see below) is a creative problem-solving competition involving students from kindergarten though college. Team members work together at length to solve a predefined problem (the Long Term problem); and present their solution to the problem at a competition. They must also generate spontaneous answers to a problem they have not seen before; this is the Spontaneous competition.
Odyssey of the Mind is administered by Creative Competitions, Inc.
Website: http://odysseyofthemind.com/