Via Slashfilm.com:

One of the biggest complaints that Star Wars fans have about the prequels (at least those who don’t enjoy them that much) is that it seems like George Lucas abandoned the tangible feel of real sets and practical effects in favor of too many computer generated imagery. The true innovation that brought Star Wars to life came from the production having such a low budget that required Lucas and his crew to be resourceful about how they created sets, spaceships, weapons and more for the galaxy far, far away. And that includes the most iconic weapon in the Star Wars universe.

Here’s a video from DigitalRev explaining how lightsabers were created from vintage camera flashes: