Perfect for the urban-planning wonk who wants to build a personal city—or the destructive child who'd like to stomp one to bits—are these tiny, customizable dioramas, which include skyscrapers that can be hacked to glow in the dark.

The adult toys, called Ittyblox, are 3D-printed by the New York/Netherlands company Shapeways, and include a variety of constituent pieces. There's this glassy, jet-black Chicago office tower, for instance, and also a cute clump of New York townhouses. Each one has a different footprint, so arranging them to fit the baseplate might require a bit of "Tetris" skill. But don't worry about troublesome zoning issues—you're the god of this Twilight Zone civilization. Read More