Trivia: For a single frame, one can see the structure that holds the Kong puppet. The first time it's still visible in modern copies at time code 00:52:36 (after the people run away on a log used as a bridge). The second one was digitally removed years ago, and it takes place when Kong exits the cave right after Ann faints. (00:52:36 - 01:05:30)
Trivia: Garrett Morris makes a cameo as the man in the car when Scott hits its roof. Morris was the first person to portray Ant-Man in a 1979 sketch for Saturday Night Live called Superhero Party.
Trivia: The bear that Jack Ryan brings home to his daughter is the exact same bear Bruce Willis brings to his son in Die Hard (both films were directed by John McTiernan). (02:06:00)
Trivia: On Burt Reynolds' hat is the shape of Florida with a star. The star marks the location of Jupiter, where Reynolds lived much of his life, had a ranch, and eventually passed away.
Trivia: During the big fight between Batman and Superman, a broken window has the same shape as Ontario, in Canada. Superman creator Joel Shuster was born in Toronto. The broken window is only ever shown from Superman's angle, not Batman's. This was confirmed by Zack Snyder as being a deliberate, if obscure, easter egg.
Trivia: The man that punches Phileas when he attempts to beg for money is the director Frank Coraci. (01:22:20)
Trivia: There are brief cameos at the start of the film by Peter Jackson as Bad Santa, who stabs Nicholas, and Garth Jennings as the Crackhead who holds hostages. Later, Cate Blanchett appears as Janine, who is hidden behind a surgical mask, and from whom Nicholas is estranged. And the film's director, Edgar Wright, is seen as the store employee pushing the cart when Nicholas walks towards the manager's office.
Trivia: For the shot where Hans Gruber falls from the top of the building, Alan Rickman was dropped by a stuntman from a 20-foot high model onto an air bag. To get the right reaction, the stunt man dropped Rickman on the count of two instead of three. Rickman said "That sounded like fun and so I decided to do it, I thought they were a bit surprised that I said I would and I was surrounded by people saying, 'You're mad, you're mad!' But no, it was fun. And it was the last shot, so if I'd broken my neck, they'd still have a movie."
Trivia: On the "subway" train, the man holding the USA Today paper is Cameron Crowe, and the woman in the seat behind him on his left is Cameron Diaz. Because "Vanilla Sky" and "Minority Report" were so close in shooting, the two directors (Crowe and Spielberg) agreed to put themselves as cameos in each other's films. (00:46:10)
Trivia: Stan Lee makes his usual cameo, this time as a patient at the asylum where Selvig is being held.
Trivia: The number A113 (which appeared in Brad Bird's previous films The Incredibles and Ratatouille) makes two appearances here. The first is on the side of Hanaway's ring in the flashback sequence, and the second is verbally as Ethan's agent ID that he recites through the phone after he escapes from the hospital. (00:14:40)
Trivia: Gene Barry and Ann Robinson, stars of the 1953 version of this movie, make a small cameo in this movie as Mary Ann's parents. They are at the end when the whole family is reunited.
Trivia: In the opening musical sequence when they jump out of the pool, the lady behind Austin can be seen laughing because her swim hat has fallen down.
Trivia: Stan Lee's cameo actually references another cameo he made as himself, in 1995's Mallrats - he's reading the script for that on the train. This marks the first time he's explicitly himself in a Marvel Cinematic Universe film (he identified himself as Stan Lee in Fantastic 4: Rise of the Silver Surfer), not just a random character. In fact Guardians of the Galaxy, Vol. 2 confirms he's actually playing the same character in every cameo, a Watcher Informant, roaming the multiverse and reporting back his discoveries. And given he's reading the Mallrats script here, that means Stan Lee himself was actually an alien being all along, observing humanity and others. And of course that means the real Stan Lee exists in the MCU, so created comics based on characters who really exist, albeit maybe in another universe...but you could go on like that forever.