I constantly astonished with the new variations of 3D printing that pop up. Slashdot links to an article discussing a powder bed system that uses a magnesium based glue and sand to essentially print stone. The implications for architecture are staggering, not in the least one explicitly considered by the creators, the possibility of using such a printer to fabricate some or all of the structure for a moon base.
When get one so I can print up an Escher-esque lawn ornament?