The marshmallow experiment is a famous test of this concept conducted by Walter Mischel at Stanford University and discussed by Daniel Goleman in his popular work. In the 1960s, a group of four-year olds were given a marshmallow and promised another, only if they could wait 20 minutes before eating the first one. Some children could wait and others could not. The researchers then followed the progress of each child into adolescence, and demonstrated that those with the ability to wait were better adjusted and more dependable (determined via surveys of their parents and teachers), and scored an average of 210 points higher on the Scholastic Aptitude Test.
This is a video clip of some game show over in japan. The whole point is to strap a rubber band to your face thats attached to a wall, and try to eat a marshmallow hanging from a string. This is hilarious!! I almost pissed myself the first time I saw this.