ET Gave Us Wi-Fi

"We own the patents on a few things we confiscated from out-of-state visitors: velcro, microwave ovens, liposuction."

- K, Men in Black

Some science fiction works will have as part of their plot that a noticeable chunk of modern technology was descended from the use of alien science/knowledge in some way: perhaps it was the reverse engineering of Imported Alien Phlebotinum, or possibly the discovery of some Lost Technology left behind by Ancient Astronauts, or maybe we got it from a Captured Super Entity. At any rate, it's not really ours.

This is usually meant to explain how we've managed so much progress in the past century or so. It can also explain why alien tech is sometimes eerily similar to human tech.

This trope is frequently used as the basis for a Historical In-Joke, the cheapest of which being that the reverse engineering happened at Area 51 and/or was a direct result of the supposed crash in Roswell That Ends Well.

Expect varied amounts of success should the writers address the many issues brought up by the characters understanding even the underlying principles of whatever Sufficiently Advanced Alien tech the source was. Same goes if they try to explain how it came to be that an alien toaster could pave the way for the World Wide Web.

Also, a healthy dose of historical revisionism may be necessary to effectively use this trope considering modern technology can be traced back to human discovery pretty easily.

On second thought, screw it: maybe most advancements from the past few decades came from a town of geniuses.

Graphic Novels/Comics

 * Scarlet Traces created by Ian Edgington and D'Israeli posits that the tech left behind by the Martians in War of the Worlds has been developed by humans with variable results.

Advertising

 * A recent Alienware advert suggests that the company's range of high-power gaming PCs was created in this way.
 * Which is unintentionally hilarious considering that anyone who knows anything about computers, or knows anyone who knows anything about computers, can make one just as powerful for maybe a third of the cost. Those aliens must really get around.
 * Before cell phones became ubiquitous, PrimeCo ran a series of commercials featuring a little pink alien who lost his cell phone on Earth and tried to get it back because "Earth wasn't ready" for their technology.
 * A tie-in ad campaign for Transformers: Revenge of the Fallen has a Cybertronian Burger King who gave the secret to delicious hamburgers to the founders of Burger King back in 1953 in exchange for a place to live. Its implied that he continues to work as their recipe man right up to the present day.

Film

 * In the first live-action Transformers movie, the technological advances of the 20th century were made by reverse engineering the captive, frozen Megatron after he was discovered in 1897.
 * The Asylum film Transmorphers has the human resistance's weaponry reverse-engineered from the alien robots'.
 * We've evidently gotten quite a bit of knowledge out of that one crashed spaceship in Independence Day. An extended version of the film explicitly states that it was used to create Earth computers, which also handwaves the vulnerability of the mothership to a computer virus.
 * The titular organization in Men in Black gets its funding from holding various patents based on alien technology. This includes velcro and a little disc thingy that's "gonna replace the compact disc."
 * Pseudo-example in The Stinger of the second Night at the Museum movie, where a cell phone left in a portrait-sized photograph prompted a guy from just after WWII to attempt to reverse engineer it. According to the photo, his name was Joey Motorola. Motorola, Inc. was founded in 1928 by Paul V. Galvin and was already making hand-held radios in 1940.

Literature

 * Hard Landing by Algis Budrys, in which a bunch of crash landed alien Joes have to get by on Earth, and one of them decides to sell alien tech to the US.
 * Reversed in A Deepness in The Sky by Vernor Vinge: space faring humans guide the development of the alien Spiders through their equivalent of the Cold War in order to achieve a suitable technological base for the repair of their fleet.
 * In the My Teacher Is an Alien series by Bruce Coville, an alien helps humanity develop television in hopes that it will slow humanity's development. He later regrets the interference.
 * Inverted and played straight in Go Mutants, where the human invention of nuclear weapons brings our planet to the attention of alien races
 * In The Man Who Fell to Earth (both book and film), alien protagonist Thomas Jerome Newton starts an Earthly corporate empire via his people's inventions (electronics, film stock, etc., all far ahead of human technology) with the intent of raising the capital he needs to fulfill his mission.
 * In Animorphs, The Andalite Chronicles, Elfangor says he talked to a guy named Bill who worked at a computer company...obviously intended to be Bill Gates. He also mentions a guy named Steve, which could indicate one of Apple's Steves.
 * In "The Warning", Visser Three's brother took a obscure human computer tech and turned him into the billionaire owner of Web Access America, the books' version of America On Line.
 * The Strugatsky Brothers' Roadside Picnic transfers this trope into the future: In a setting Twenty Minutes in The Future, humanity makes progress by studying and finding uses for alien artefacts dropped on Earth by an unknown extraterrestrial civilization.
 * In The Helmsman Saga, it is stated a few civilizations were given the push toward interstellar travel by the Empire's Escape pods.

Live-Action TV

 * In a variation, the powers-that-be on Stargate SG-1 were initially disappointed that not enough exploitable alien tech was coming back with the teams. As time passes and they bring in more tech, it starts filtering down to the public. They even fielded a (barely functional) energy weapon.
 * In an Alternate Timeline where the stargate was never discovered, technology is noticeably behind the main timeline standard.
 * The Doctor Who episode "Dalek" features a tech mogul who steals alien tech. According to him, Broadband is from Roswell.
 * A subversion in "Day of the Moon", in which it is revealed
 * This is the explicit purpose of the original Torchwood, as revealed in "Army of Ghosts:" to defend the British Empire against Aliens and taking their stuff to make them stronger. The United Nations Intelligence Taskforce/ Unified Intelligence Taskforce (U.N.I.T.) has a similar goal.
 * The sphere on Seven Days was based on Roswell tech. Other more mundane technology was also said to have come from Roswell.
 * Preventing the reverse of this--keeping Human/Federation tech out of the hands of alien civilizations whose society might be altered by it--is one of the original reasons for Star Trek's Prime Directive.
 * The second-season Star Trek Enterprise episode "Carbon Creek" implies that Vulcans stranded on Earth during The Fifties sold Velcro to support a child's education.
 * Star Trek Voyager. In "Future's End" the IT revolution happens because a time ship crash lands next to a 60's hippie who becomes an 80's yuppie (probably based on Steve Jobs) by reverse-engineering its technology. Since the Federation tend to put all of human knowledge into the computer of every single starship, Sterling was able to quickly learn what he needs to just by asking the right questions. He also claims to have tapped out the timeship's potential for new technology, even though he hasn't invented, say, transporters or anything.
 * This is reasonable if the remaining knowledge requires materials we don't have (say, Dilithium crystals, or 50 KG of Yittrium), energy requirements we can't meet (transporters require 15 TW to run), or manufacturing processes we can't reproduce (large scale nano-engineering)
 * Dark Skies, and the conspiracy folklore it's based on, supposes that modern technology was invented by reverse-engineering material from the famous Roswell incident.
 * The Event:
 * Sliders episode "The Return of Maggie Beckett" showcased a parallel world where The Greys gave Earth new technologies and allowed for significant advances. Rembrandt says he always believed this was the case for his own world and cites several technologies, including Velcro. (Both this and the Enterprise episode listed above were written by the same guy: Chris Black.)

Real Life

 * In a lovely Not Funny Anymore (or Hilarious in Hindsight, your pick) moment, Gillian Anderson apparently believes this.
 * A quick Google search confirms she isn't the only one. This little factoid made it hard to search off-wiki for more examples of this trope.
 * An episode of The History Channel's UFO Hunters investigated real-life rumors that the SR-71 and B-2 Spirit bomber were a result of this.
 * Erich von Daniken is famous for claims that the first human civilizations were created by aliens, similar to the Stargate film
 * That's because Stargate was based in part on his books.
 * There is a theory out there that says computers were reverse-engineered from an UFO, or something like that, under the rationale that no human could have ever conceived an universal machine that could simulate human thought. Don't expect IT professionals or anyone who knows the history of computing to take this one well.
 * Hell, take anyone who says this and force feed them the life and accomplishments of John von Neumann. You might want to add a few servings of Nikola Tesla as well (all of both at once would melt their little bitty brains). Humans Are Special. "Aliens" just carve Incomprehensible Landscapes.
 * Ada Lovelace wrote the first computer program in 1843. Charles Babbage designed (but did not build) the first computer, called a Difference Engine, in the 1820s. There is an awesome webcomic about them.
 * Then again, the ancient Greeks had a device like a computer a millennium before that. It was for calculating the positions of celestial bodies relative to Earth, something useful for both human travelers and Ancient Astronauts looking for a way home.
 * Just to give the trope name some credibility, one of the first consumer wi-fi routers was the Apple AirPort Base Station. It looks remarkably like a flying saucer.
 * According to a quote in this article, cell phone technology was derived from black hole research.

Western Animation

 * Similar to the 2007 film, Transformers Animated has the robotic technology of the 22nd century all reverse-engineered from Megatron's dormant head.
 * According to the Men in Black animated series, most advanced human technology was granted by a benevolent advanced alien race. Computers, hard drives and the Clapper are cited as examples and their patent revenue is The Men in Black's primary source of financing.

Video Games

 * In Assassin's Creed I, the Templars (and by extension, society) are implied to have gotten all of our advances from reverse-engineering alien artifacts (with a couple of failures, see Philadelphia Experiment (done by by US government, not Templars)). Later on in the series,
 * In Assassin's Creed Revelations, it's confirmed that from a vision given by one of these, which had been implied in Assassin's Creed II. Also, in a brief scene at the beginning of the "Battle of Forli" DLC for II, a brief activation of the Apple shows images of designs that Leonardo da Vinci (who was watching the Apple) would later set to paper.
 * In Mass Effect, it is explained that the Human race's technology was jumped forward about 200 years after they found ancient Prothean ruins on Mars.
 * The third game reveals that