In the Simpsons, Homer's brother Herb (who's car company was bankrupted by Homer in an earlier episode) invents a baby translator. The Baby Translator does just what it sounds like: it translates babies crys, goo ga's and gurgles into what they really mean.
Now many years later, there's an app for that as they say. The $30 Cry Translator for the iPhone tells you if the cry is "hungry, sleepy, stressed, annoyed or bored." They claim 96% accuracy regardless of the age of the child.
Almost makes me want to try it on Glenn Beck!