http://www.instructables.com/id/Super-Cheap-and-Easy-Fog-Chiller/ I made one of these last night for my fog machine, it really helps keep that fog on the ground where it belongs! I improved the design a little by using some of that expanding foam spray insulation to seal it up and waterproof it. Better yet, if you have a fog machine and access to a good laser pointer, you can build this: http://www.instructables.com/id/Laser-Vortex/ I'm going to try and find a green laser pointer locally tonight and make one up by the weekend. It's surprisingly simple to build. That whole website is full of cool shit you can make on the cheap.