Mary-Kate and Ashley Olsen's real birthday, as many an 11-year-old girl can tell you, is June 13, 1986, but their first few months on earth don't really count--they didn't accomplish all that much. That changed in October 1986. Selected from a lineup for their nice smiles, the Olsen twins landed a shared part as newborn Michelle Tanner on ABC's Full House. In September 1987, one of them (your guess is as good as ours) was trotted out in front of the camera in the arms of actor John Stamos. Since then, in their trajectory from the Full House twins...