Jurassic Park was released 21 years ago this week. Kottke recommends the above short documentary that reveals the technology behind the remarkably convincing special effects:
When Spielberg originally conceived the movie, he was going to use stop-motion dinosaurs. [Visual effects company Industrial Light & Magic] was tasked with providing motion blur to make them look more realistic. But in their spare time, a few engineers made a fully digital T. Rex skeleton and when the producers saw it, they flipped out and scrapped the stop-motion entirely. Fun story.
The Dish 