Wow...killer shot. I have tried this too, but I have wanted to get a "horror movie" feel to it. I tried it a while back, and wanted to get the rays to be strong, so I "threw" powder around. Other then making a mess on the floor, I failed. I used a desk lamp for my light source. Man.. you gave me inspiration to try this again. I might hook up one of my fog machines in the room and see if I can get it to drift out of the door.
You did awesome with this one.