Designer Sean Yoo’s Opus Shelving recently made its way to the open arms of Design Within Reach, where its indoor/outdoor flexibility and lightweight building materials are making the piece’s sexy sensibility even more desirable. Inspired by ancient Roman wall-building techniques and similar structural elements found in nature, the Opus shelving system makes use of 100% recyclable polyproplene (the same material used in motorcycle helmets) to aid in stack-ability and durability. This combination make the Opus easily adaptable as a bookcase, a room divider, or anything else you might choose to create out of easy-to-move building blocks. I was thinking four of these assembled in the shape of a square could make a nice kid-pen (assuming the sections for books are filled in with cement), but that’s just one idea. Check it out here, then see if you can get out of there without buying anything else…