Remember Tetris? Then Tetrad Flat will look familiar to you. The modular wooden shelving system is flat-packed and comes with a metal backing in different colors. We like the Tansu chest configuration shown in the photo, although we can see how this would be a tempting set of stairs for kids to climb. The trademark Tetris-shaped shelves provide fun cubbyhole spaces for storage and display in the nursery or playroom. Each set includes 1 each of 5 shapes. The blocks can be attached to one another, affixed to the wall or left free floating. Tetrad Flat shelves are 9" deep. They come in white or birch finish with a variety of metal backing colors. Available here for $750.