TV Telephone Etiquette

Doesn't anyone say "goodbye" anymore?

—AJ, The Fairly OddParents

The inability for main characters who answer the phone to either hang up the phone, acknowledge the caller, or say any "good-bye" equivalent. This is because phone calls are often done solely for exposition's sake.

If there is no split-screen and the other end is not heard by the audience, characters are also required to repeat back everything the person on the other end says to them.

Examples of TV Telephone Etiquette include:

Film

In a nutshell: Three minutes of people in movies hanging up without saying goodbye.
A Running Gag in the film Eight Heads In A Duffel Bag involves the primary antagonist's inability to have a normal phone conversation, usually in the form of destroying the receiver instead of saying goodbye and hanging up.
In Layer Cake, the protagonist remarks "That's rude, Mr. Dragan", after the caller (a psychopathic Serbian hitman) hangs up without saying goodbye.

Literature

Star Wars: Emperor Palpatine needs no comm etiquette, as is pointed out in Shadows of the Empire. He has a habit of stating what he wants without greeting, then ending the conversation without any kind of farewell. His subordinates have learned to accept this as 'just one of those things'.

Live Action TV

In Law and Order (and later Law and Order SVU) Captain Cragan invariably answered the phone by yelling "What?".
NCIS: They're repeat offenders, none worse than Gibbs, of course.
On Covert Affairs, Annie calls Auggie on this early in an episode, saying that "normal people" say good-bye. He replies that it's just one more reason not to. This becomes a very minor comedic subplot, until the end of the episode, when Auggie is going off on his own to seek revenge. Annie knows something is wrong when he says . . .

Auggie: Good-bye, Annie.

"What?" is Miss Parker of The Pretender's signature greeting.
The Mentalist.
24. Nobody ever says goodbye on the phone, which is a little funny since Jack spends at least half the series on one.
Characters on Seinfeld seemed to have a particular aversion to saying goodbye.
Debra Morgan on Dexter is also really bad with this.
Happens on Nikita a lot too, although it's kind of understandable.
The Brady Bunch: Mike calls a friend of his about a problem; he jumps right into the topic and doesn't say goodbye. Robert Reed wrote one of his many scathing memos about this scene.
Gaia Moore greets callers with "speak".
- Truth in Television: A common phone greeting in Mexico is "Diga", which means "speak".

Web Original

In The Guild, the leader of the evil guild is overtly rude over the phone. He answers the phone by stating the activity that you're interrupting, like "Journalling!" He also hangs up abruptly without saying goodbye, which confuses Cyd.

Western Animation

Lampshaded in one episode of The Fairly OddParents, Timmy is talking on the phone with Chester and AJ (in a three way split screen). After the conversation is over he hangs up as does Chester. AJ is still hanging on the line when he realizes the other two hung up. He looks at the camera and asks "Doesn't anyone say goodbye anymore?"
Played for comedy in The Life and Times of Tim, when Tim bungles a a call from a prospective employer by hanging up when he thinks the conversation is over. After a pause, the caller continues speaking, not realizing that he's hung up.

Real Life

In South Korea, when a phone conversation is over, the callers simply hang up. Saying goodbye is not needed, although they may make a certain "Hmm" sound, indicating that they're about to hang up.