Mighty Mouths

What do you think of when you hear the word "ventriloquism"?  A showman with a wisecracking wooden boy on his lap?  There's more to ventriloquism than verbal jousting between a man and his dummy.  In this hour of To the Best of Our Knowledge, we'll explore the cultural history of ventriloquism.  Also, Nancy Cartwright's life as a 10-year-old boy - she's the voice of that cartoon underachiever, Bart Simpson.