Over the weekend I registered for the Clone Army Builder's Guild forum as I've heard nothing but good things about the group. I was looking through the forum topics and found a link to the video tutorial above on how to make 'lightsaber effects' in GIMP, a free, open-source photo editing software that has similar functionality as Photoshop.
A quick use of the YouTube search and it appears that this video is the most viewed tutorial on the site for this topic (it doesn't mean it's the best, of course, but that's a story for another time). Nine minutes later and a little practice and you could be adding glowing lightsabers, eyes, or power cores to your minifig creations or vignettes.
The one place where this tutorial is wanting is in how to generate believable light effects from said blade. Although the end result looks quite good, it doesn't cast the light and shadows you would expect. If anyone knows a fix for this, please let us know.
Thanks to the folks at the CABG for pointing this out!