Telecom Tree

In our modern day and age, when communication needs to take place, we can do it with landlines, Cell Phones, text messages, and/or The Internet.

It is a really good thing, too, because when the hero(es) need help, the Telecom Tree comes into play.

There's a situation that's too big for our main character to handle on his/her own. But he/she knows a good number of people, perhaps because they are popular and friendly, or just from Walking the Earth. Either way, it's time to enlist their aid, and because the heroes are the heroes, anyone called on the phone is only too happy to pitch in and help. Not only that, but they're willing to call the next person in the chain of phone numbers to help get the giant group effort underway that much sooner.

A variation common in older productions: the viewer is treated to a splitscreen as more and more people become involved in sending the message out.

This trope may be considered the modern day equivalent to Gondor Calls for Aid, though usually it's more friends than Gondor Calls for Aid's "friends, enemies, anyone the heroes can get to pitch in".

Anime

 * This happens without the hero knowing in Monster as a result of his making so many friends while Walking the Earth.

Film

 * In Practical Magic, when witches Gillian and Sally need extra help to get rid of the nasty ex-boyfriend ghost of Jimmy Angelov they activate the town Phone Tree, normally used to let all the moms know of school snow days. It turns out that despite the Gossipy Hens talking smack about the witch sisters, most of the women in town are not only genuinely curious about them, but happy to pitch in because they can identify strongly with having a bad ex who won't go away without a female friend having her back.
 * In Spy Kids 3, Game Over, the Cortez children send out a desperate wrist phone call to "Everybody!". Their parents and grandparents show up, as well as their uncle Machete, Floop and the reformed Minion, the reformed Uncle and Giggles families, the Mad Scientist, the guy who owned the theme park at the start of the second movie and his son.
 * Brandon and his friends do this for Jason Nesmith in Galaxy Quest.
 * In Legally Blonde 2, one scene involved the sorority the lead is now in activating an emergency phone tree of ex-sorority members.
 * Buckaroo Banzai has the Blue Blaze irregulars, a group of various people who help him out of tight spots. No matter what it is or who they are.
 * In a movie about retired Mafia members living in Florida, one of the group uses the fact that he has kept in touch with every other former Mafioso to have retired to the greater Miami area to gather a posse to raid the base of a crime lord who had kidnapped the daughter of another member of the group. This leads to a hilarious scene where a freighter owned by a drug lord is attacked by a busload of gun-toting senior citizens.

Music

 * In the music video for Tracy Lawrence's "Find Out Who Your Friends Are", a redneck's truck breaks down in the middle of nowhere. He places one cell call to a friend before his phone fails, he then gives up. Fortunately for him, his friend has friends, and those friends have friends... until a giant convoy of friends is seen converging on him, in everything from a tractor to a Jeep to a Corvette.

Literature

 * Working to a deadline? Need a mob to storm the castle? Just tell a member of the Ogg family. The rest will take care of itself.
 * Known as the ghost-to-ghost hookup in The Three Investigators books.
 * In The Executioner novel Dixie Convoy, the truckers helping Mack Bolan use CB radio to spread a message from one coast of the US to the others.

Live Action TV

 * This is pretty much the whole point of the titular organisation in Global Frequency. Though only a couple of agents are actively involved in any particular crisis, there are a few times when the call goes out to all 1,001 members for any help they can provide (notably the TV pilot and the last issue of the comics).
 * Doctor Who series 6 (or 32) does this twice. Firstly, A Good Man Goes To War is all about this, with the Doctor calling in several favours to raise an army to . Secondly, in The Wedding of River Song, River, Amy and Rory  . While this doesn't activatly do anything, it breaks the Doctor out of his Heroic BSOD and reminds him that however much death and destruction he leaves in his wake, he's still a hero, and his life is worth something.

Newspaper Comics

 * In Zits, Pierce calculates that in order to get 700 people to turn up to his Wild Teen Party he has to inform exactly one person (Brittney) and let the word spread. It works.

Theater

 * In Bye Bye Birdie the teenagers of Sweet Apple Ohio are seen doing a tree in "The Telephone Hour."

Truth in Television

 * On a couple of foreign school trips, there was a phone tree set up in case of serious problems.
 * Flash Mobs are created through ever-widening circles of text messaging.
 * A man was arrested in a foreign country. He posted one message to Twitter, and the resulting Telecom Tree response web alerted his bosses and got the problem resolved with the foreign authorities.
 * Several companies with multiple retail locations have a phone tree set up with each store in a given area responsible for calling one other pre-designated store, so that (for instance) if an unsuccessful shoplifter successfully flees, other locations can be quickly forewarned.

Web Comic

 * Shows up in El Goonish Shive after Hedge kidnaps Elliot.

Web Original

 * There She Is!, in its final episode, has Nabi the cat  All the friends and relatives who have been with them since episode 2 pitch in and help get him there, including calling forward to help stop Doki so Nabi has his chance to get there.

Western Animation

 * In Beverly Hills Teens if you wanted to get everybody together you told Switchboard, and pretended it was a secret.
 * The finale of Justice League Unlimited doesn't go tree style, but they do summon every single member for the final fight, even allowing the bad guys to fight to save the world.
 * Whenever she has to travel to some remote location, Kim Possible can always count on someone she has helped before to provide free transportation.
 * There is an episode or a longer special of The Fairly OddParents where Timmy sends a message over the internet requesting help from all the kids in the world.
 * Marge Simpson has a diagram of her phone tree.
 * In Tex Avery's Tortoise Beats Hare, Bugs Bunny has challenged Cecil Turtle to a footrace. Cecil calls his old buddy Chester and together they set up a Ringer Ploy over a phone tree.