Trivia: If you compare the battle between Darth Vader and Obi-Wan in this one to the battle in Episode 1, this fight seems very slow and careful. There's a couple of reasons for this - partly, while David Prowse got replaced by an expert sword fighter (Darth Vader was played by, in total, about 5 or 6 people for different things like stunts, voice, etc.), Alec Guinness had to stay himself, and he probably wasn't capable of leaping all over the place. However, more important is the fact that the lit up blades of the lightsabres in Episode 4 were made of wooden doweling (not unlike a broom handle) and if they hit them together, they snapped. These were replaced in the subsequent films with much stronger carbon fibre rods (similar to fishing rods) which explains the ferocity of the lightsabre duels in the later films. The motor within the handle spun the blade which was wrapped in reflective tape, creating the flickering effect. This only showed up when the lighting used was at the right angle. Thus during the Ben / Vader duel it explains why their lightsabres disappear at various points when they point the blade almost directly at the camera.
Trivia: For a decent replica Star Wars laser sound, hold one end of a metal Slinky around your ear, and let the other end drop and hit the floor. It is neat. I would suggest you avoid letting others see you do this unless you have a chance to explain! The real sound was made by striking a metal stabilizing cable of a high tension wire electrical tower.
Trivia: Not really a mistake, but apparently if you go up to a telegraph pole and hit one of the metal wire support cables with a piece of solid copper it will make a laser blaster sound. I take no responsibility for major internal or external injuries or loss of respect from peers. For a safer alternative, if you have a spring type garage door just tap (or even flick with your finger) the spring.
Trivia: Lightsabers are made out of a selection of camera parts - you can get the schematics for them on the internet, and make your own. However, the right camera parts are very hard to get hold of, because firstly they were around in the 70's/80's, and also because Star Wars fans keep buying them.
Trivia: The huge alien skeleton that C-3PO passes in Tatooine was left in the desert by the crew. When they returned to the area in the year 2000 to make "Star Wars: Episode II - Attack of the Clones", the skeleton was still there 23 years later.
Trivia: The film was almost cancelled on the first day when Tunisia experienced its worst desert storm in half a century, destroying most of the set.
Trivia: Originally Obi-Wan Kenobi survived the duel with Darth Vader and fled aboard the Millennium Falcon. But the character had very little to do with the rest of the film, and George Lucas decided that he should be killed off. Alec Guinness threatened to quit the production over the change, but Lucas convinced him that the change was better for the overall story.