Here we are!
3D Printer - High Resolution - Printing Alien Skull - YouTube
Unfortunately, the author of the blog and the machines designer seems to have dropped off the face of the earth shortly after completing the software he designed for the machine.
3D Printer
You can follow the progress of someone who has made a very similar machine, as well as posted a bit more information about the materials that they used and how they did it here:
3 D L P rint
I believe both just use a DLP projector to harden photo reactive resin in vat one 2d cross section at a time. It's a technique that creates a very high resolution part and it's the process used by most professional 3d printers. If you are feeling adventurous and want something in the future that will give you much finer detail than an extruder can you may want look into building one of these.