James Waldby wrote:

I got an email pointing at an interesting site about sculpting
metal by a method analogous to fast-prototyping-in-plastic machines,
but in stainless steel + bronze.

It works great, too.

I had them make some parts for me from an .stl file.
It isn't a super fine finish, but it does clean up to flat metal quite nicely.

http://www.exone.com/eng/technology/x1-prometal/

--Winston