This appears in this morning's Dallas Morning News. Have a very blessed Nativity. *** In this corner, ladies and gentlemen, we have Leonardo DiCaprio, adorable star of "Titanic," "Catch Me If You Can," and now, "The Aviator." In the other, we have - oh, pick a name. Clark Gable, Cary Grant, even Jimmy Stewart, for cryin' out loud. Notice any difference? Such comparisons are prompted by DiCaprio's newest release, "The Aviator," in which he portrays aeronautics engineer, Hollywood mogul, and big-time player Howard Hughes. As Entertainment Weekly's Owen Gleiberman puts it, DiCaprio is "a dynamo of an actor" but "at...