Remember those old toys? You'd turn them upside down and they'd make a mooing sound. Flip them again, another moo. What's old is new again. Turn your iPhone into an entertaining sound device that moos whenever you flip it from back to front or front to back. It won't build world peace or create unlimited renewable energy but it may amuse your three-year-old for several minutes. Small scale victories can be just as sweet. (Works on iPod touch but requires an external speaker)
Tips: Turn your sound ON. (Muted iPhones do not moo). Turn the iPhone glass down. And then glass up. Mooooo.