Star Wars aficionados know the third chapter in George Lucas' blockbuster series was briefly called Revenge of the Jedi before its title was switched to Return of the Jedi.
However, by the time the filmmaker changed his mind, a teaser trailer had already been produced and thousands of posters already printed (Lucasfilm wound up selling the posters with the scrapped title to Star Wars fans, creating an instant collector's item).
But, what about that trailer? It was released in theaters, showing Luke Skywalker with a blue (rather than green) lightsaber, and Obi-Wan Kenobi before the "spirit" effects were added. Now you can see the teaser for yourself, along with the other original trailers for previous Star Wars films, including Empire Strikes Back, on the franchise's YouTube page.
Lucas returned to the third film's temporary title when writing the prequels, hence Star Wars: Episode III -- Revenge of the Sith.