New Scientist:

George Whitesides from Harvard University and colleagues have created a three-legged robot lined with tubes filled with a mixture of methane and oxygen. When an electrical spark ignites the gases, the combustion reaction generates bursts of pressure that propel the robot aloft. "By actuating all three legs simultaneously, we caused the robot to jump more than 30 times its height," write the team. As the height of the jump was limited by the size of the experimental chamber, they think it could spring twice as high without the attached tubing.