Split-Screen Phone Call

Split Screen is one of those Camera Tricks that were never really popular... except for depicting people calling each other on the telephone, that is.

A common cartoon gag with this is where the shouting character's portion of screen expands and/or the timid character's portion shrinks. Very useful when the tide of the argument shifts, moving that diagonal back and forth showing who's in charge. It's also common for cartoon characters to reach across the screen split and directly interact with the person on the other end of the line. It is sometimes parodied when the split is removed and it is revealed that the characters are actually next to each other.

It can extend to more than just two screens, thanks to things like three-way calling and call waiting.

Anime and Manga

 * Martian Successor Nadesico features technology that can allow free-floating 'screens' to pop up just about anywhere, and it appears that the caller has some control over the size and positioning of their image, so multi-way conversations will oftem involve multiple screens literally jostling for attention, the winner being the character with the best 'Screen-Fu' (generally Ruri).

Comic Books

 * Frequently used in comics, usually with a jagged diagonal gutter between two triangular panels. Sometimes the phone cords will be positioned to suggest the two recievers are directly connected to each other.

Film
"General: "And be sure to feed my goldfish."
 * A famous movie example is Pillow Talk...
 * ...whose use of this trope was parodied in Down With Love. The phone scene between Ewan McGregor and Renee Zellweger used the Split Screen in a rather... uhm... interesting way to imply that they were directly interacting.
 * One of the cell phone calls in Mean Girls splits the screen in five.
 * Bye Bye Birdie naturally did this a little in "The Telephone Hour." The original Broadway production split the stage into over a dozen areas for that number.
 * There's one of these in Snatch. The director's DVD commentary reveals that in order to cut costs the two sides of the phone conversation between Cousin Avi and Doug the Head were shot at separate times on the same physical piece of film - which is why the timing is slightly off.
 * Ruthless People has this trope twice between Carol and Chief Benton; first discussing to arrest Sam Stone and again after Sam was released from jail.
 * Used in Run Lola Run when Manny and Lola talk on the phone.
 * Parodied in The Naked Gun 33 1/3. One end of the conversation is in a phone box, the other in an apartment. In the background, a hobo walks past the phone box only to cross the split screen line and find himself in the apartment, which he then proceeds to burgle.
 * Two times in When Harry Met Sally:
 * Sally calls Harry one night and the two of them chat while watching "Casablanca". The split-screen is set up so that they're each in their own bedroom, in their own bed, but it looks like they're sharing a bed.
 * A three-way set-up has Jess and Marie in bed together when Harry calls Jess and Sally calls Marie. When Harry and Sally tell their respective friends that they had sex the night before, Jess and Marie turn to each other and say in unison, "They did it!"
 * Parodied in Austin Powers when a normal split-screen call keeps adding new elements until there are eight split-screens and the original caller has moved on to something else.

Fish flakes enter the goldfish's screen

General: "Not too much."

A net takes some fish flakes away"

Live-Action TV

 * One Coupling episode did this with an answerphone. The entire episode was an object lesson on weird/cool stuff you can do with splitscreen.
 * Believe it or not, The X Files did this one between Skinner, Mulder, and Scully ... and played it for laughs.
 * It's happened in Lizzie Mcguire. I think that had a triple-split screen, and then quadruple when Lizzie's brother tried to listen in.
 * The season 4 finale of Doctor Who has one of these; admittedly it's not a phone but a video conference, but still.
 * It was arguably a standard shot of a video screen that was, in turn, showing a Split Screen Phone Call.
 * 24 does this a lot.
 * According to the DVD extras for the first season, 24’s entire split-screen look was born of necessity when the editor realised the pilot involved a lot of phone calls. He was using a common computer editing setup that showed two separate takes running side-by-side and decided to apply that visual metaphor in the actual show.
 * The Middleman uses this a lot, to good effect.
 * Seinfeld had a few of these, and sometimes played with the concept with call waiting.
 * Commonly done on Top Gear when two presenters are in separate vehicles speaking to one another by radio or cell phone.
 * Taken to extremes on Glee, during a conference call between all the members of the Glee club that are in on Finn's Baby Trap.
 * This trope appears in one episode of Family Matters involving Steve, Laura, Maxine, Waldo, and Eddie.
 * The Roswell episode "I Married An Alien" is partly done as a Bewitched style sitcom; at one point there's a four-way split-screen as the real characters and the sitcom characters carry on separate phone conversations, until they get mixed up and start responding to the wrong conversation.
 * Used in the "Cheating" short shown on Mystery Science Theater 3000, which gave it a Bye Bye Birdie riff.
 * How I Met Your Mother uses this trope constantly and finds new ways to play with it.
 * Angel. Played for Laughs in The Teaser of "Provider". A Victim of the Week is being chased by an unseen monster, stumbles in the rain, finds himself clasping an Angel Investigations flyer, rushes to a phone booth and begins to dial frantically. We then Split Screen to Team Angel staring at the phone waiting for a call -- only for the screen to split again to show a pizza parlor cook picking up the phone. Apparently the wrong number was printed on the flyer.

Music

 * The John Mayer song "Split Screen Sadness" references this trope, where a girlfriend tells her boyfriend over the phone some bad news.
 * Occurs in the music video for "Girls Just Want to Have Fun" by Cyndi Lauper

Video Games

 * Used when overhearing phone conversations in Ghost Trick. It's implied in-game that the protagonist, who has the ability to travel through phone lines, actually can see both ends of the conversation at once.

Web Original

 * "A Call To Arms", Chapter 1 of  ~LG15: the resistance~  plays with this effect a lot (including a bit at the end where the two cameras meet).
 * This Cracked video explains why it's scary to answer phone calls in movies.
 * "Where was I? Where the hell did I go? Why was David Bowie there?"

Western Animation

 * Used all the time in 6Teen.
 * Done at least twice with Candace and Jeremy on Phineas and Ferb.
 * Super Mario World did the parody version with Yoshi and Oogtar. ("Yoshi hear Oogtar too good! Who need telephone?")
 * Spongebob SquarePants also did the parody version with Spongebob and Patrick.
 * The Simpsons had a scene with tons of little screens as rumours spread about Michael Jackson coming to Springfield.
 * The episode "24 Minutes", a parody of 24, features many split screens. Martin even hurts himself when he manually closes his split screen.
 * Looney Tunes Back in Action has Bugs and Daffy do this when the former was planning to help the latter get his job back. And they even push one another.
 * Also taken to extremes in one 1999 Arthur episode, where there was a 4—4 split! Obviously, 16 people were shown on the phone at once in a single scene. Each screen also faded to black as each caller hung up. When Binky Barnes ended up being the last guy talking, some Hilarity Ensued™.
 * The Merrie Melodies cartoon The Bear's Tale, has a split screen phone call scene between Red Riding Hood and Goldilocks who are both using payphones.
 * It was a cartoon made by the Texan. And he really loved this trope. I personnally recommend Thugs With Dirty Mugs.
 * Shows up commonly on Jimmy Two-Shoes.
 * In The Adventures of Sonic the Hedgehog, Dr. Robotnik parodies this trope in a way that has to be seen to be believed.
 * "Oh, my gosh! My dog's found a chainsaw!!!"

Real Life

 * Check your local news channel!