They won't forget the Yankee Doodle Dandy in his old neighborhood any time soon. A memorial to the late James Cagney was unveiled Thursday on a block of East 91st Street in New York City, and Mayor David Dinkins changed the street signs to say James Cagney Place. The guests included Mary Tyler Moore, director Milos Forman and former heavyweight champ Floyd Patterson. Moore told the crowd that, like her, Cangey was a diabetic and she accepted a check from the Cagney Foundation on behalf of the Juvenile Diabetes Foundation.