Man, this took way longer than I thought it would. Hats off to all the people at Lucasfilm who have to animate lightsabers. I feel your pain. True, you probably use the latest version of rotoscoping technology in your work, but still-- it's a hard job.
To my five readers: enjoy the following story. Later on, I might blog the original photos so you have an idea of what kinds of changes had to be made to get the right effect.
Our story begins a long time ago, in a galaxy far, far away...