Many new parents can relate to the frustration of trying to figure out the exact needs of their baby. Are they hungry? Do they need changed? Whether it's a piercing wail to have their diaper checked, ...

Communicating with a 6-month-old baby may seem like a gimmick--a Hollywood plot device dreamed up for a funny movie (like the New Age baby in Meet the Fockers, to be precise). But in fact, baby sign ...