1. Rachel McAdam’s wig in Mean Girls was made of human hair.
2. After watching the dailies for Pirates of the Caribbean: The Curse of the Black Pearl, Disney executives thought Johnny Depp was ruining the movie with his performance.
3. Whitney Houston was one of the producers of The Princess Diaries.
4. Christian Bale screen tested for Batman Begins in one of the old Batsuits created for Val Kilmer for 1995's Batman Forever.
Also, Bale performed his screen test opposite Amy Adams — who did the screen test as a favor to the producers.
5. Irish actor Stuart Townsend was originally cast as Aragorn in The Lord of the Rings, but was fired by the film's director, Peter Jackson, one day before filming started.
Viggo Mortensen, who of course replaced Townsend, agreed to take the role after his son told him to do it.
6. Gabrielle Union agreed to star in Bring It On after she was passed on for a role in Sugar & Spice.
7. The idea for The 40-Year-Old Virgin came from a sketch Steve Carell created while at Chicago's Second City.
8. NSYNC's Joey Fatone, JC Chasez, and Chris Kirkpatrick were extras (as Jedi) in two scenes of Star Wars: Episode II. Their scenes were ultimately cut from the movie.
According to Fatone, the band was asked to do the cameo because the daughters of George Lucas and the film's producer, Rick McCallum, were fans of the band.
9. In order to play the role of Effie in Dreamgirls, Jennifer Hudson was told to gain 20 pounds and get lip injections.
10. Juno’s hamburger phone was actually a prize possession that belonged to the movie’s screenwriter, Diablo Cody.
11. Leonardo DiCaprio was interested in playing Christian in Moulin Rouge!, but the film's director, Baz Luhrmann, quashed the idea after hearing him sing.
DiCaprio told Variety that he sang "Lean on Me" for Luhrmann and that after hearing him sing the high note Luhrmann turned to him and said, "Yes, D, I don’t know if this conversation should continue."
12. Beyoncé was Disney's first choice to voice Princess Tiana in The Princess and the Frog, but she reportedly lost out on the role because she refused to audition.
According to Jen Rudin, who did the voice casting for the film, other celebs that wanted the role were Tyra Banks, Jennifer Hudson, and Alicia Keys.
13. Scottish actor Dougray Scott was originally cast as Wolverine in X-Men, but after the movie he was working on at the time, Mission: Impossible II, went overschedule he was replaced by Hugh Jackman.
Funny enough, at the time, hardcore fans of the comics were not thrilled that Jackman had replaced Scott, they thought he was "too tall and handsome for the role."
14. Sofia Coppola, who wrote and directed Lost In Translation, still has no idea what Bill Murray whispered into Scarlett Johansson's ear at the end of the movie.
15. Megan Mullally was fired from a role in Finding Nemo because she refused to use the high-pitched voice she used for her Will & Grace character, Karen Walker.
Mullally said that when she signed for the role, Disney Pixar had agreed to let her use any voice she wanted.
16. Spider-Man 3's writer-director, Sam Raimi, was very unhappy with how the film turned out and was planning on making a fourth film to make up for it, and to end the franchise on a high note.
17. The late Alan Rickman — who had hazel eyes — would wear black contact lenses for his role as Severus Snape in the Harry Potter films.
Originally producers tried to make Daniel Radcliffe's blue eyes green (like Harry's) in the Sorcerer's Stone by having him wear colored contacts. But he ended up being allergic to them and so they decided to leave them blue.
18. Meryl Streep's performance as Miranda Priestly in The Devil Wears Prada was partially inspired by Clint Eastwood.
Streep told Variety, "The voice I got from Clint Eastwood. He never, ever, ever raises his voice and everyone has to lean in to listen, and he is automatically the most powerful person in the room."