It is a business peopled with larger-than-life characters who inspire the public's adulation as well as the rumour mills and gossip factories. Little wonder that many an idle Hollywood tale suddenly erupts into an urban legend that refuses to go away, no matter how much it is denied or explained.
It's astonishing, for instance, how many movie fans still believe that the line "Play it again, Sam", was uttered in the movie Casablanca. It happens to be one of the most famous misquotes in movie history, but it still ended up as the title of a Woody Allen movie, helping to entrench the legend.
As a public service then, to save you any future embarrassment, herewith a selection of movie legends voted most likely to be believed:
3 Men and a Baby
Long after 3 Men and a Baby had been a box office smash and had gone into the video stores, a couple hired it one day, and spotted what they were convinced was a ghost in one of the scenes: when Jack's mother comes to look at Mary, supposedly, the ghost of a little boy is standing in a doorway. The viewers contacted the media, others suddenly spotted the ghost, and the urban legend exploded: the apartment where the movie was shot had been the scene of the boy's death, and his ghost still haunted the room where the boy had slept. One small problem with that: the apartment was a Hollywood set. And the ghost? a cardboard cut-out of Jack.
2001: A Space Odyssey
When the ultimate space travel movie hit the screens, hip audiences were quick to spot in-jokes perpetrated by director Stanley Kubrick. One of these, the name of the super-intelligent computer, HAL, was said to be a dig at computer giant IBM. The author of the script, Arthur C Clarke, supposedly disguised it by reducing each letter one space: I to H, B to A and M to L. The rumour has become a full-blown urban legend, despite Clarke himself claiming it had been unintentional, and that he would have changed it if he'd noticed in time.
Plan 9 from Outer Space
Urban legend has it that the legendary horror actor Bella Lugosi died of a heart attack a few days into the shooting of what has been described as the worst movie ever made. He appeared only briefly, and his character suddenly appeared as a taller person with a mask covering his face. The facts: Lugosi died before the movie was made, and director Ed Wood simply took left-over footage from one of his uncompleted projects, and wrote the screenplay around the scenes to make it appear that Lugosi was a star of Plan 9. The original title, Grave Robbers from Outer Space, would thus have been far more appropriate. Ironically, the urban legend lives on in Ed Wood, the Tim Burton movie on the amazingly bad director.
The Jack Nicholson horror classic was such a disturbing movie, and the star's performance so convincingly maniacal, it was easy to believe that there was as much to his "act" as met the eye.
The urban legend emerged that Nicholson did go a little mad during the infamous scene in which he broke a door down with an axe to get at his screen wife. Supposedly, he had to be physically restrained after working himself into a frenzy with the axe. Fact: the axe was made of rubber; Nicholson remained sane (by his standards, anyway).
The Wizard of Oz
This most innocent of movies has a deeply controversial behind-the-scenes history: Margaret Hamilton (The Wicked Witch of the West) was badly burned during her disappearance from Munchkinland, and her stand-in was injured by an exploding broom during a stunt shot.
Rumours emerged of wild, drunken orgies by the Munchkin actors, and that Toto was killed on set and had to be replaced. While these rumours have faded, a new one emerged in recent years as the film became more and more popular on video: that a man committed suicide on the set, during filming, by hanging himself from a tree on the set. And, goes the urban legend, by freeze-framing the video, you can see his body swinging from a tree in the shadowy background during the scene where Dorothy discovers the Tin Woodsman. Fact: a large bird is flapping its wings in the background.
My Cousin Vinny
When Marisa Tomei won an unlikely best supporting actress Oscar for her role in this unassuming little comedy, the rumour mill got buzzing, and threw up an urban legend: Marisa Tomei had received her Oscar statue in error. Jack Palance, so the legend goes, went on stage to present the Oscar, but couldn't read the winner's name in the envelope. He took a chance and called out Tomei's name instead of the actual winner.
Fact: at every Oscar ceremony, two members of the accounting firm PriceWaterhouseCoopers stand in the wings. Their instructions: if a presenter announces the wrong name, they are required to head straight for the podium and announce that a mistake had been made.
The movies they never made
Finally, a category of movie that gets everyone's blood boiling, and the urban legend wheels rolling at their fastest: so-called snuff movies, in which someone is deliberately killed for the camera, since this supposedly gives a certain kind of perverse pleasure to a certain kind of perverted viewer who will pay a fortune to see such a film.
So convincing are the claims about such movies, and so emotional do the claimants become about the truth of their claims, it is almost impossible to convince a believer that the snuff film is the greatest urban legend of the movie industry.
Fact: neither the FBI or Scotland Yard has ever found evidence of a real snuff film made for commercial distribution. As senior FBI researcher Paul Lanning has put it, "Simulated snuff movies using special effects are so realistic, there is no point in risking life in jail."
So relax. No one's coming to take you away to make you star in their horror movie.
* Scientist did not name a new species of velociraptor found during the making of Jurassic Park after Steven Spielberg. An ankylosaur that had been found a few years earlier still needed a name and was given one amalgamated from the movie's cast list. A raptor found during the filming was named Utahraptor.
* Anthony Hopkins did not pop into screenings of Silence of the Lambs and scare the pants off movie-goers by tapping them on the shoulder at the end of the show and asking them "Did you enjoy the film?"
* Robert Redford did not go on a TV talk show and give out his phone card number for free calls to celbrate winning a big lawsuit. Nor did Steve McQueen, Paul Newman, Sammy Davis Jr or Burt Reynolds.
* And Eddie Murphy did not pay for a little old lady's hotel stay after scaring her half to death in an elevator when he shouted "Sit Lady!" to his dog.