(at around 31 mins) At one point in the film, Milo asks Andrew "What's it all about?" This was the tagline of both Alfie (1966) and its remake Alfie (2004), which respectively starred Michael Caine and Jude Law in the title role.
The original stage production of "Sleuth", by Anthony Shaffer, opened on Broadway on November 12, 1970. It originally starred Anthony Quayle as Andrew, and Keith Baxter as Milo, ran for 1,222 performances, and won the 1971 Tony Award for the Best Play.
Jude Law's character states near the end that he's never been to Coney Island. Another of Law's characters, Gigilo Joe from AI : Artificial Intelligence, almost got there with his friend David, but was captured shortly before they arrived.