I'm going to throw this thread in here - not really sure where else it might fit - has anyone used http://www.shapeways.com/ to have a 3d prototype made of a design before machining it? I was made aware of their existence by someone who had one of my 3d designs printed for his own use - I was making a part in brass and he wanted a plastic one - cheap. I let him have my 3d file so he could have a friend with a 3d printer make one for him- he ended up sending it to shapeways. The interesting thing is the variety of materials that they can use - including brass and stainless, silver gold, etc. I have not used them myself yet - but I'm sure I will at some point. My part in their base plastic was only $7-8. You upload an STL and the tell you materials that they will make it from and analyze the part to make sure it will print properly. Check them out. You can even set up a tore to sell your item made and shipped by them. Could be a very useful resource, I think! Anyone used them before?