3D printing is really neat. At my previous University, we had access to a company called Rapidtech (their office is in one of our buildings). They dealt with 3d printing all day long. I had a project where I made a CAD drawing and had them print out my part in 3D. These printers will print complex parts that cannot be machined on a CNC machine.
There are certain machines that will also print in color. Very useful for FEA analysis.
The medical field LOVES 3D printing. They're able to take your MRI/CAT scan and reproduce your part in 3D to the right scale. That way the doctors can examine bone cancer, fracture, etc without having to open you up. Not to mention, they'll already know what to do before going into surgery. Bones in your legs can be replaced with Titanium that's printed to your exact spec. No more trial and error on the surgeon's part.