Rapid prototyping and fabrication are one of those technologies that you don’t appreciate (or even know are in use) until you walk into someplace like the Boston Fab Lab at MIT and run into them face-first. Things we buy in the store just sort of pop into being without the consumer knowing anything about how they were made, be it by injecting liquid plastic into a mold or using a robot to mill a block of metal into an intricate shape. Anyway, a student named Mark used a ShopBot CNC machine (the best way to describe one is a …