I thought it was five films:
The Godfather I & II
The Deer Hunter
Dog Day Afternoon
The Conversation
What was the other one??
(That is a pretty amazing stat, by the way, whether it’s 5 OR 6)
The Godfather III. (Although according to Cazale’s filmography in the IMDB, he was only in “archival” footage).
Thanks, Max, looks like the legend is “kinda” true and mostly not. I appreciate your clearing that up. I will never tell that story again.
And Mjollnir, you’re forgiven. 
In “The Mummy Returns” the train that the Mummy rides through the desert in is the same train that was used in “Lawrence of Arabia.”
The house that Brendan Frasier and Rachael Weisz are shown living in is actually Ridley Scott’s house in London.
The reason they decided to set “The Mummy Returns” ten years after the first one is because writer/director Stephen Sommers refused to work with any actor under ten years of age. Which is why the boy in the movie is ten years old. Stephen Sommers said and I quote: “I didn’t want to work with any babies or annoying five year olds.”
The scene where they dig up the Mummy was filmed in England and it rained every day they filmed. They later digitally removed all the rain during post production because the scene obviously takes place in the middle of the desert.
I included Godfather III in my count in case someone wanted to nitpick me about it. Cazale is in it, but in footage from the earlier films (he had died long before it came out and his character was killed in GII). Maybe Coppola wanted to include it for good luck – and it did seem to work. 
I haven’t actually verified this, but I think it’s true: Daisy Duck’s first appearance in a film was in “Fantasia 2000.” (Daisy was developed in the comic strip and did not appear in any early films. She was also not a part of “Ducktails,” so wasn’t in that movie.)
As far as I know, this is correct.
One of the ghost hunting devices used in the new THIRTEEN GHOSTS is an unmodified Sybian sex machine.
Willem Dafoe and David Bowie have appeared in three movies together. Do you know what they were?
Easy: The Last Temptation of Christ – Bowie is Pilate, Dafoe is Jesus.
Harder: Basquait – Bowie is Andy Warhol, Dafoe is the electrician.
Really Obscure: The Hunger – Bowie is a vampire, Dafoe is “2nd Phone Booth Youth” (one of his first credited movie roles).
If you were wondering, “1st Phone Booth Youth” was played by John Pankow, best known as Ira on “Mad About You”.
Musician/actress Ann Magnuson made her film debut in The Hunger as “Young Woman from Disco”. David Bowie gropes her bare breasts and drinks her blood.
Magnuson later came out as a lesbian.
Magnuson made an uncredited appearance in the movie Tank Girl, as The Madame. She sang Cole Porter’s “Let’s Do It”, and tried to pimp Tank Girl’s young friend Sam out to a creepy old john (“Rat Face”) with a thing for schoolgirls.
That creepy old john was played by Iggy Pop, whose song “Funtime” (a collaboration with Bowie) was featured in The Hunger but does not appear on the soundtrack album.
Ann Magnuson is gay?
Dammit!
I had such a weird kid crush on her. Wasn’t she a regular on a sitcom? Anyone remember?
I’ve got to go rent The Hunger now.
Here’s some trivia Bruce Springsteen’s sister plays the murderer in the Sleepaway Camp sequels.
In nearly all of director Sam Raimi’s films, the yellow Oldsmobile, from his first movie, The Evil Dead, (and it’s sequels) makes a cameo appearance.
I just saw the Olds’ in the trailer for Spiderman. Spidey plops down onto the hood.
Raimi’s Oldsmobile can also be seen in:
Darkman: When Darkman is dangling from the helicopter, and dipping into traffic, you can see not only see the Olds’ but the people in the front seat are Bruce Campbell and a woman. They are dressed as the characters from Evil Dead.
The Gift: Cate Blanchett’s character drives the Olds.
etc…
Another note: Bruce Campbell often makes cameos in Raimi’s films as well, usually disguised or not showing his face. This is called, “shemping.” See Bruce Campbell’s official site for more info about “shemping.”
OK, since you’ve brought up “shemping. . . .”
This is not confirmed trivia, but I think it’s true.
In The Best Years of Our Lives, I think Moe Howard has an uncredited role as a motorist, only half of whose face can be seen as he pokes it out his car window and barks at someone.
Brother Shemp had a much larger role in the movie.
Watch the end credits to the absolute bitter end. As the final credits are rolling up, and the score music fades out, you can hear the sound of the oxygen tanks Ripley & Newt are sleeping in. Then, an ominous slithering sound. It’s the sound of a second stowaway alien skulking aobut and ready to “impregnate” Ripley.
Aside from that, in “Mulholland Drive” – Camille takes the name “Rita” from a movie poster for the film “Gilda” starring Rita Hayworth.
The plot of “Gilda” (roughly summed up) is as follows: Glenn Ford becomes the lackey for an Argentinian mobster played by George Macready. Macready marries Gilda (Rita Hayworth) a hussy who has had a past liasion with Ford (significantly, their backstory is alluded to, but never, ever explained in the course of the movie). The Hayworth and Ford characters hate/love each other. Hayworth makes Ford’s life miserable, until Macready’s character is presumed dead. Hayworth then marries Ford. Ford turns the tables on Hayworth, tormenting her mercilessly, essentially punishing her for being a teasing wench.
That’s pretty much the basis for Mullholland Drive’s backstory: Camille and Diane have had an affair; Camille dumps Diane to marry Adam (the director - who is boss of both women); Diane feels humiliated and insulted by Camille at the dinner party; Diane has a long extended fantasy/dream about Camille being seperated from her priviledged station and “punished” for her tart, teasing behavior.