The first 3-D feature ever released by a major American studio. House of Wax (1953) went into production first, but Columbia rushed "Man in the Dark" - shooting it in a mere 11 days - to get it into theaters just days before "Wax" opened. (Bwana Devil (1952) preceded both of them, but United Artists was not considered a major studio in the early 1950s.)
The cackling animatronic woman in Steve's dream sequence is called a "Laffing Sal". It was built by the Philadelphia Toboggan Company and stood nearly seven feet tall. Many of these were installed at fun houses or "dark rides" at amusement parks across the country. This one, at the Ocean Park Pier, was called "Laffing Gertrude".
In a separately filmed trailer, Edmond O'Brien talks to the audience about the film and about "Three Dimension".
Just before O'Brien and Trotter head to the pier he said they're going to need money and "I haven't got change of a quarter". When they exit the cab at the pier he pays the driver. Must have been one cheap cab ride.
Ted de Corsia ("Lefty") played the killer in the film The Naked City (1948), while Horace McMahon ("Arnie") played Detective Lieutenant Mike Parker in the TV show Naked City (1958).