Creators add details no one need notice.

Two spring immediately to mind for me:

In Airplane II, when the shuttle takes off, the music to Battlestar Galactica is playing. The navigator is played by Kent McCord, who played Captain Troy on the show.

In Boogie Nights, there’s a scene where Dirk Diggler (Mark Wahlberg) and Reed Rothchild (John C. Reilly) are in a recording studio, working on an album. The first song played is “You Got the Touch,” which is featured prominently in Transformers: The Movie. I actually noticed this in the theater the first time I saw the flick.

So if Woodward and Bernstein were killed before they could expose Nixon, how did the chain of events play out such that Gerald Ford wound up being President?

He didn’t- he remained Vice President during Nixon’s four terms.

Okay, Larry, I’M confused. Jurph says

Am I reading it wrong? I think Snooooopy and I saw the same thing.

All the little stickers on things like panels, etc. in the various Star Trek shows since TNG say things like “Objects in mirror are closer than they appear.” Also, there’s a plaque on the bridge of the Enterprise which makes reference to “Admirial Roddenberry,” IIRC.

Lots of Terry Gilliam’s animations for Monty Python were clipped from famous works of art.

In one of his movies, Cary Grant improves a line where he says he killed Archie Leach for crossing him. Archie Leach is Cary Grant’s real name.

Superdude – The historical reference is a reference to a historical occurance, ie; President Ford tripping as he stepped out of Air Force One.

In the context of Watchmen, it was made by having Vice President Ford trip as he stepped out of Air Force Two.

It’s an alternate reality, but Ford is still a klutz, president or not.

I think I see. The confusion for me was stemming from Ford being addressed as President, when he was actually still VP.

If I try to explain that any better, I’ll confuse myself.

If Watergate had never been exposed, would Ford have ever been VP? I honestly forget what specifically led to Agnew resigning.

Remember the old show “Quark”? Sci-fi comedy about interstellar garbagemen. Had a lot of in-jokes, including “There he is – behind the roddenberry bush!”

Never mind – Agnew resigned over allegations of financial wrongdoing when he was Governor of Maryland. Never did like him.

Sunset Boulevard is heavy with in-jokes – the broadest one being that the plot mirrors the plot of Erich von Stroheim’s infamous Queen Kelly, in which Gloria Swanson played the eponymous role. I’m sure a lot more people got the “Rosebud” joke in Citizen Kane when they first saw it than had a clue about Queen Kelly.

More recently, Batman Begins, which is so self-consciously Jungian that it’s almost absurd – and yet somehow I suspect that most folks with their butts in the seat for a superhero flick might not catch it.It may as well be called The Individuation of Bruce Wayne. Batman is Bruce Wayne’s “shadow.” A big part of the plot revolves around an anima projection thing that Bruce has going on with Rachel, tied to his externalizing of ideas of justice and boundaries.

And I have trouble believing nobody would have blown the whistle on Nixon even if Woodward and Bernstein had been shot.

Perhaps in a different universe, Felt would have tipped off the Democrats and they would have hired their own team of burglars to dig up the dirt, leading to a spiralling tit-for-tat war between the parties that in 1984 would have allowed the Libertarians to get a ticket elected by a nation completely pissed at both the Democrats and Republicans.

And in 1992, the Feds would finally outlaw paragraph-length sentences.

In The West Wing, the young-looking Josh Lyman is the Deputy Chief of Staff, and the main Congressional liaison.

In Doonesbury in 1993, Josh Lyman was the White House Deputy Cabinet Liaison. “But… But you’re just a baby!” says Joanie Caucus.

I’m a little late in noticing this, true, but it took until 2003 for even the obsessively crazed West Wing fan site to stumble over it. And yes, IMDb says that the Doonesbury strips on Josh’s wall are the Josh Lyman ones.

In watching the original Alien, the phallic imagery of the alien’s body and life cycle (from the dual symbolic rapes of the egg implantation and hatchling’s emergence, to the shape of the adult’s head) is probably more obvious than is the feminine, yonic, and vaginal imagery associated with the “Mother” ship Nostromo. (I certainly didn’t catch it all on my first viewing.) I won’t claim that this is a complete list (and it’s been a long time since I’ve seen it), but consider: the soothing, womb-like atmosphere in the suspended-animation-pod room and in the limited-access communications room; deltoid-shaped doors (significance? think of Anais Nin’s “The Delta of Venus”); long, dark, cramped passageways; the maternal persona (“Mother”) and voice of the ship computer… and there’s probably other details.
In The Wicker Man, when Sgt. Howie confronts Lord Summerisle with his suspicions of foul play, a rather dark and ominous oil painting hangs high on a wall in the background. Its rather imposing subject may be at first unfamiliar to us “mainlanders,” but the end of the movie reveals what it was…

I bumped this, because, while I have gotten good results, I am sure that fans of clever writters, as opposed to visual medium creators, can come up with throwaway lines, and descriptions of background characters.

Futurama used this joke as well.

Leroy Brown. Cool Username. And you’re from Florida. How encyclopedic.

Several extremely referential songs spring to mind, which are catchy enough for you to enjoy in and of themselves but even moreso enjoyable when you catch the allusions:

McLean’s American Pie. Famous ballad alluding to famous landmarks in rock n roll history, including the deaths of many rockers.

Joel’s We Didn’t Start The Fire. Refers to newmaking events and personalities from the 50s, 60s, 70s & 80s.

D’Angelo’s Brown Sugar. Obstinsively a love song, it’s really an ode to smoking marijuana, specifically the strain called Brown Sugar although Chocolate Thai gets a shout out, too – one of the better “weed songs” around.

Pink Floyd’s The Dark Side of The Moon is supposedly an alternate soundtrack to The Wizard of Oz.

In Alan Moore’s “League of Extraordinary Gentlement” (the first book), the characters recruit the Invisible Man by going to “Rosa Coote’s Correctional Academy for Wayward Gentlewomen.” Miss Cootes is the title character in “Miss Cootes’ Confession” an erotic story (involving the whip, natch) published in “The Pearl” in the 1880s.

Actually, it was ‘They should at least have a Roddenberry’s’ - it was a listing of restaurants the planet might have.

Actually, there was no list. Wasn’t this The Problem With Poplars? The crew was looking for food and Leela did say the planet had Roddenberries.

Actually, I didn’t mean to use “actually.” It comes off snarky when someone starts a contradictory post the same way as the post in question. Didn’t mean it that way at all. Sorry.