website link:
http://www.diylife.com/2007/08/16/ma...ing-laser-mod/

Video:
[ame="http://www.metacafe.com/watch/756433/laser_flashlight_hack/"]Laser Flashlight Hack! - Video[/ame]

Turn a Mag-lite into a burning laser? To boost the geek factor, you will be able to tell all your friends that this is a laser made from a DVD-burner, how ubergeeky is that? Alright, stop drooling so I can finish this post.

How and why someone thought of doing this is not the point, doing it is the fun part. I'm not sure what you would do with a burning laser, but I'm sure you'll think of something, or many things. Just be careful and whatever you do don't burn people or point that killer laser at anyone's eyes. Can't see the video? Here is the link. The detailed instructions for how to do this are at Instructables.