Dutch artist Sam Abbott has designed the world's first fully-functional skateboard built and modeled with a 3D printer. Abbott's gnarly creation won a competition organized by 3DprintUK.
Because the body of the skateboard is longer than printer, Abbott had to print three separate pieces, then connect them with connector pins. The board is ridable--as can be seen in the video--though Abbott wouldn't suggest doing rail slides or riding down a long set of stairs yet. http://www.youtube.com/watch?v=NABeSso09EI#t=44