In a scene in *How to Marry a Millionaire, *Lauren Bacall is saying how she loves older men. She names a few, including “that old guy in African Queen.” The reference is to Humphrey Bogart, Bacall’s husband, 25 years her senior.
What other examples are there?
In Working Girl, Harrison Ford joked about how he received his trademark scar.
In His Girl Friday, Cary Grant refers to “Archie Leach” – his real name.
Also, the actor played by Ralph Bellamy is described by Grant as looking like “the actor, Ralph Bellamy.”
More seriously, in Bend it Lick Beckham, Parminder Nagra talks to her coach about the scarring on her leg. The scars are real and Nagra describes the actual incident, when some hot oil burned her.
In Ocean’s 12, when Julia Roberts is called upon to impersonate Julia Roberts, doesn’t she question her similarity to that woman?
In Rosemary’s Baby, when Rosemary meets Terry Gionoffrio in the laundry room, she says “I thought you were Angela Dorian,” the actress’s real name.
In the book, Terry looked like Anna Marie Albergetti.
In Tapeheads, the FBI agent played by Jello (Dead Kennedys) Biafra suggested framing one of the protagonists for a crime, “Like we did to Jello Biafra.” Kind of weak, really.
In Spider-Man 2, Spidey lands after a 30-floor drop and staggers around saying “My back! My back!” Tobey Maguire hurt his back in the first Spider-Man and whined about it just a bit too much for director Sam Raimi’s liking.
In Spider-Man 2 there’s a scene where Tobey Maguire tumbles to the ground and gets up complaining, “Oh, my back”. I’ve been told that’s a joke about the back problems that almost kept Maguire from signing on for the movie. I have no way of verifying that, so maybe someone can correct me.
ETA: Krokodiiiiil!
One year, there was a controversy at CSI when George Eads was late to the first day’s shooting; the producers thought this was a contract ploy and talked about firing him. Eads claimed he just overslept and was kept on.
When the first episode of the season began, someone says to his character, Nick Stokes, “You’re late.” He replied something like “Me?”
There was a outtake in Bruce Almighty where Jennifer Anniston is reading a supermarket tabloid and says “She’s such a good actress and all they talk about is her hair.” I really thought that should have made it in the movie.
“I can’t believe there’s some scum like that that would murder his wife” – OJ Simpson, some movie made in the 80s.
In “Die Hard” Alan Rickman muses that his nemesis might be a bartender, Bruce Willis’s former day job. OK, a lot of actors wait tables and such, but I think that was deliberate.
After James Doohan had a heart attack, he appeared in Star Trek II: The Wrath of Khan. During an inspection, Scotty says that Dr. McCoy recently pulled him through “a wee bout.” Kirk looks questioningly at him, and McCoy says, “Shore leave!”
At the end of Ocean’s 13, George Clooney tells Brad Pitt to “settle down, have a few kids…” (An obvious reference to Pitt’s relationship and ever-growing family with Angelina Jolie.) And Brad Pitt tells George Clooney to “try to keep the weight off between jobs next time.” (A reference to Clooney gaining weight for Syriana.)
(Quotes are approximate…)
Sorta in reverse:
In one of the Knight Rider (1992ish) made for TV movies, James Doohan appears as himself, I think trying to get money out of an ATM. He gets knocked on the head somehow, and starts mumbling something like, “Captain, I can’t give ya any more paairrrrr.”
In “Take Her, She’s Mine,” Jimmy Stewart’s character was frequently confused for Jimmy Stewart.
Not a movie per se, but Boris Karlof was approached and offered the part of the evil brother in Arsendi and Old Lace on broadway by being quoted the line about the evil brother always being thought to look like Boris Karlof.
I just wish he had done Jonathan in the movie as well.
Paging Dr. Freud…
May have been, but it was actually Paul Gleason as the chief of police who made that speculation, referring to the fact that McLane could recognize a fake I.D.
In Arsenic and Old Lace, Johnny Brewster is referred to as looking like Boris Karloff. Raymond Massey played him in the movie, but Karloff actually played the role on Broadway, so it sort of qualifies in a second-hand way.
“She’s not Lebanese, she’s Punjabi!” 
I can’t remember the name of the movie, but there was a Rock Hudson flick where he was staying in a men-only hotel. His wife/girlfriend wanted to visit him, so she disguised herself as a man (with fake facial hair and everything). There’s a scene where he kisses her (while she’s still in her disguise), and some passerbys are shocked to see him apparently kissing a man. I always wondered if that was a deliberate wink to the fact that Rock Hudson was (“officially” closeted but really everyone knew) gay.