I have been following the progress of 3D printers which are very fascinating. They are becoming affordable for the home user in addition to being simpler to use.
3D printing takes a three-dimensional data file and creates a solid object by printing it layer by layer. Great for engineers, designers, and hobbyists. Excellent for proof of concepts and making little unique gadgets.
It is amazing to see what people have come up with for unique designs. I especially like the geometrical 3D shapes.