The good people at NoVa Labs have a laser cutter that goes by the name on Mongo. Mongo is a 100 Watt laser that will work on sheets about 3 feet by 2 feet, it also has a cool rotary attachment, when you hook it up instead of gantry moving in the Y axis it instead rotates the item you are working on and you can get some pretty cool results.
I bought $60 or so of glasses in Ikea so I had plenty of material to experiment with.
The work flow is done primarily via Inkscape and GIMP, basically lots of tweaking with settings till it looks around right, and then export as DXF. There is then some additional adjustment that happens int he laser software when you import it but for the most part they turn out pretty well. The laser software will also take BMPs natively, but all you can do is engrave, so you can’t tweak many settings.