Put a key on the hook, and the weight makes the garage door open up to reveal the 1/64-scale car of your choice. Regardless of what you put in the garage, this is an awesome way to hang your keys.

Sgt. Kenneth R. Storvick monitors the progress of a 3D-printing job at Corps Base Camp Lejeune, North Carolina - image: DoD. Marines would be able to extract a "near infinite set of different UAS ...