Unlike the previous Star Wars films, which were shot both on soundstages and on location, Star Wars: Episode III - Revenge of the Sith was filmed entirely in the studio. The only location work was a background plate shot during the production of Episode II.
Having Han Solo frozen in carbonite was (at least in part) due to the fact that they were not sure that Harrison Ford would return for a third film. When the original Star Wars was made, Carrie Fisher and Mark Hammill were signed for a three picture deal, but Ford refused.
There is no mystical significance in the color of Mace Windu's lightsaber. Samuel L. Jackson, after a joking conversation with stunt coordinator Nick Gillard, asked Lucas if he could have a purple lightsaber and Lucas agreed. In an interview on UK TV, Jackson said he "thought it would be cool".
"The Star Wars Holiday Special", which aired on November 17, 1978, marked the first appearance of the character Boba Fett, in an animated segment of the show. This special has never been released on video -- however, bootleg home-recorded videos have been circulating for years and are now all over the internet. George Lucas once remarked at an Australian convention that "If I had the time and a sledgehammer, I would track down every bootlegged copy of that program and smash it."
At one point, Lucas planned for the character of Luke Skywalker, along with his aunt and uncle, to be midgets. According to some sources, Leia's line when Luke rescues her ("Aren't you a little short for a stormtrooper?") is a remnant of this story idea.