Trivia: During a speech in Toronto, Bradley Cooper told audiences that people in Las Vegas didn't even notice they were filming a movie, even though he had bloody tiger scratches on his neck, and Justin Bartha was beet red, nobody stopped to look.
Trivia: Miranda Cosgrove, who plays Summer Hathaway, actually has a good voice and plays guitar. She had to take a 45-minute class to learn how to sing badly for the scene where she sang "Memories."
Trivia: The boardwalk scenes were filmed on location at the Santa Cruz Beach Boardwalk in Santa Cruz, California.
Trivia: George Clooney (Everett) was going to sing "Man of Constant Sorrow" for the film but his singing voice was very poor so he ended up lip-synching the songs instead. He said "I'm not my aunt [referring to the late singer/actress Rosemary Clooney, best known for her role in "A White Christmas" (1954)]. I decided it would be easier to just do a passionate lip-sync." He was so nervous that the tapes of his singing would get out that he returned to the studio to ensure all the evidence had been erased. The musical director of the film confirmed this but said "George is a very good singer but that style of music is very difficult and one almost has to grow up singing it in order to sing it convincingly. George did a really good version of the tune but it wasn't as good as he wanted."
Trivia: Kevin Smith once happened upon a demonstration against this movie by a group of Catholics. Since nobody recognized him, he simply joined in.
Trivia: The voice behind Roz, the number 1 of the Child Detection Agency and the undercover secretary, is actually a man.
Trivia: In the scene after Hiccup finally gets Toothless' new tail fin to work, and the two are relaxing after they fly through the fire ball, the two are greeted by a group of tiny dragons. This little dragon was actually what Toothless was originally going to be, as he was in the book, until they changed him to a dragon big enough for Hiccup to ride to suit the movie. (00:46:15)
Trivia: In the scene where Nicky goes to heaven and meets his mother, a man walks in and she introduces the man as Chubbs. Chubbs was Adam Sandler's golf instructor in Happy Gilmore.
Trivia: Dropping Ted while he was on the stretcher was not intended, it accidentally collapsed. When it did, the Farrelly brothers called cut to make sure Ben Stiller was alright, and then just left it in.
Trivia: The prom night band is punk-rock group Good Charlotte.
Trivia: The knife that is given to Louis by the pirates is the exact same knife that Buck had in the previous film.
Trivia: Executive Producer Peter Billingsly has a cameo as the ticket agent at the airport. Peter also played Ralphie Parker in the 1983 movie favorite A Christmas Story.
Trivia: The house with the blue door (William's residence) was formerly the home of the movie's screenplay writer, Richard Curtis.
Trivia: David Graf's wife Kathryn has a cameo in this movie as an airline stewardess.
Trivia: The "old gangster movie" that's on the TV in Harry's apartment is the fictional movie "Angels with Filthy Souls," which was seen in the movie "Home Alone." The director wanted a detective movie for the scene, and said: "We needed something and I hadn’t figured out what I was going to put on that TV yet...Just as a laugh, we got the movie that they shot for Home Alone off of YouTube...We could never beat it!"
Trivia: The Titans first encounter Slade while he's stealing a power crystal. They mistake him at first for the Marvel character, Deadpool and proceed to argue back and forth about him being Deadpool or not. With him saying that he's not Deadpool, that actually Deadpool should be saying he's not Slade. This is a joke and reference to the fact that the designer of Deadpool based his looks, abilities, and character originally off Slade/Deathstroke because he wanted to draw Deathstroke. Until Deadpool's backstory and personality were changed to what we know him as today.
Trivia: Jeff East, who plays teenage Clark Kent, was dubbed over with Christopher Reeves' voice. The only time Jeff's actual voice is heard is when he shouts in excitement after jumping past the speeding train.
Trivia: As Rocky flies his tricycle over the fence to aid Ginger with the launch ramp, he flashes the European "flipping the bird sign" - index and middle fingers extended - to Mrs. Tweedy.