Trivia: Hitchcock's cameo appearance, a signature feature of his films, takes place near the end. He is seen outside a phone box when Jack is making a call.
Trivia: All of the scenes in this movie were shot in only one take and in one scene the technique really shows. When Jimmy Stewart is drunk, he ad-libbed hiccuping while he was talking. Cary Grant, not expecting the comic relief, had to look down at the floor to keep from laughing (you can see him grinning and collecting himself).
Trivia: When trying to describe Bruce to a friend Grant says "He looks like, uhh, that fella in the movies, Ralph Bellamy." Bruce was in fact played by Ralph Bellamy.
Trivia: Hitchcock's cameo comes twelve minutes into the movie - he can be seen wearing a hat and coat and reading a newspaper after Joel McCrea leaves the hotel.