It's arguably become the best-known catchphrase from the show. Whenever the ship's crew needed extraction from an alien world, they simply got in touch with Scotty, who would beam them up using a transporter which as created to avoid the special effects costs if they were to show the ship landing on the planets instead. Which is a natty piece of trivia (as is the fact that the original effect was created using a sheet of kitchen foil and some carefully-placed lights before compositing it over the scene), but what's probably lesser know is nobody ever says Beam me up, Scotty in the original series. It's one of those weird famous misquotes that has somehow filtered through into popular culture despite being wrong, like Play it again Sam or Sam Worthingon is talented. There's been similar phrases Scotty, beam us up etc but nobody has said the famous phrase in any Star Trek movie or series.