Just to show that CO2 laser cutters need not be complicated or expensive
http://www.skyko.com/halloween/tombstones.jpg
These were cut out of 1 inch foam (fumes vented!) using a free 50 watt medical CO2 laser saved from going to the junkyard by me. I simply made a lens holder (znse lens 2.0" F.L. ebay $25) with a forced air nozzle and bolted it to the head of my cnc bedmill. I attached the articulated arm of the laser to the lens, put about 5-10psi coming out the nozzle and cut the foam as fast as my mill could move (about 120IPM at the time...faster now).
I have since collected several more scrap lasers...some working, some not, but have yet to find the jewel I really want...a Coherent Diamond or Synrad Firestar of sufficient wattage to cut thin steel...
One day maybe.