Thanks for the nice comments!!
I wish people could see this (and all of the other set ups I have done) in person as they look really awesome and much better seeing the way my garage lights up.
NRGlite - yes I do use fog in all of my shots. I try to use just enough to highlight the beams. If I use more, it does not look good in the photograph as it creates a haze that glows.
gozart - the stands I use are actually ring stands and burette clamps, like used in holding chemistry apparatus. A LPF member, Marco Polo was the first I have seen use this method and it is by far my favorite way of mounting lasers. Go to Amazon an put intheir seach engine, Ring Stands, and Burette Clamp and you will see what is available. I have also built some of my own stands that can hold multiple lasers and some that can hold a laser and diffraction grating.
This past weekend I set up everything the same way but added fan diffraction gratings in between the mirrors creating a load of beams going into the long rectangular mirrors, and those being reflected at various angles. Those pics will get posted soon.