In this month's issue of Popular Science (page 36) there is an article about 3-D printers that you have to see if you haven't heard about this yet.
Essentially, they have a machine which, much like a 2-D inkjet printer, shoots out layers of plastic and wax to create a full 3-dimensional object. Once the "printing" is complete, the object is placed in an oven to melt the wax away and you're left with your object. Right now, it looks like they're doing coffee mugs and basic toys (things without moving parts), but the possibilities and amazing!
popsci.com doesn't have a link to the story on the web so you'll have to pick up the magazine itself, but here is a link to one of the systems they talk about: