The dinosaur called "Velociraptor" in the 1993 Jurassic Park movie was not actually a Velociraptor at all. They are much smaller, probably half the height of what you see in the film. If anything, that's a Deinonychus terrorizing everybody.
Depending on your particular sphere of geekery, this is either shocking news, or something you heard years ago and are sick of people complaining about. I'm closer to the latter, and I'd always assumed that the error was a simple case of Hollywood wanting a more impressive-looking monster. Not so, according to a 2008 article by dino-blogger extraordinaire Brian Switek. I saw this piece in a discussion on Twitter this morning, and was genuinely surprised to learn that the great Velociraptor/Deinonychus switcheroo had its origins in taxonomic confusion—similar, in some ways, to the debate currently going on with Triceratops and Torosaurus.
Discovered and described by Yale paleontologist John Ostrom in the 1960s, Deinonychus had a large sickle-claw on each foot, long arms with grasping hands, and a stiffened tail that would have helped the animal keep its balance as it ran after prey. The genus changed how people thought about dinosaurs, suggesting that they were much more active and dynamic than had been supposed previously.
This new view of dinosaurs, in part, inspired the 1988 book Predatory Dinosaurs of the World by paleo-artist Gregory S. Paul. Not only was the volume chock-full of illustrations of feathered dinosaurs, but it also attempted to revise some dinosaur taxonomy. Paul noted the similarities between the skeletons of the Velociraptor from Mongolia and the Deinonychus skeletons from North America. They were so similar, in fact, that he decided to group the Deinonychus fossils under the name Velociraptor, as the older name took precedence according to the rules by which organisms are named.
Paleontologists did not agree with this change--Velociraptor was kept distinct from Deinonychus--but Paul's book was a hit with the general public. And one of the people who read the book was author Michael Crichton.
Finally, given that this is a Great Moments in Pedantry post, it would be remiss for me not to point out that, whether you're talking about Velociraptor or Deinonychus, a proper illustration should probably include feathers.
Smithsonian Dinosaur Tracking blog: You say "Velociraptor", I say "Deinonychus"
Pictured: A mistake.