Hey...I was thinking recently that using co2 to produce jets of smoke would be pretty simple, and reasonably safe. As long as you are a few feet from thenozzle, there should be no problems with freezing (I have a little bit of experience with liquid co2, from playing paintball. Once upon a time, I managed to get a valve stuck, venting co2 right onto my wrist. 3rd degree burn, biggest blister I've ever seen, and becuase it was on my wrist, for months afterwards the burnt area would bleed just a bit--everytime I'd flex my wrist, it'd crack the scab a bit. but if you are even a foot away, it shouldn't harm you, I'd think), and bulk tanks of co2 aren't that much to rent. Does anyone know much on them? I cannot find tons on google....has anyone used them? am I wrong about how safe they are? Can I build a system myself/has anyone here done it, or can I buy one cheaply? Thanks!