You can watch your drawings come to life when you play the new computer game "Crayon Physics Deluxe." They results look like they come from a 5-year-old’s coloring book -- a world of crinkled notebook paper and crayon scribbles. But this game is actually much more than it appears.
It works like this: There is a ball in one place and a star in another. You must move the ball to the star by using virtual crayons to draw the physical objects that make it possible to transport the ball to its goal. In an iPhone version of the game you draw by touching your finger to the screen; the PC version uses a mouse.
But the game gives physical properties to your scribbles -- they seem imbued with their own weight, and obey gravity and momentum. You can draw a simple plank to move the ball from point A to point B, or an elaborate contraption of ramps and hinges and wheels. You can look at some of the amazing solutions players have come up with here and here.