Sustainable concrete has captured the imagination of always provocative Popular Mechanics. A recent web article explores radical new ways to green concrete. Most structural engineers are well versed in supplemental cementitous materials like fly ash and blast furnace slag, but have you considered rice husks, sewage sludge, and geopolymers? The article also suggests using prcelain from recycled toilets for aggregate and hempcrete blocks as an alternate to CMU. Finally, a PM article wouldn't be complete without some exploration of space. Strategies are discussed for converting moonrocks to traditional or sulfur-based concretes.