Ok, now this is a bit wild and crazy, but still worth mentioning. A London man has created what is likely the world's first 3D printer that flies. Basically it is a drone which has a module attached that can shoot out a chemical composition. When the chemical hits the air it turns to a foam like material. This drone was created to help in moving dangerous objects, but the technology could be modified for a variety of uses. More details are here: http://3dprint.com/3331/flying-3d-printer/

Basically it could eventually be modified to become a flying 3d printer which can fly up to bridges or other out of reach areas to do repairs via 3d printing. What are your thought? Here is a video of the 3d printing drone: