Called Hold On Tight Shelf by Colleen & Eric is a modern, minimalist dream, and its approach to storage includes a built-in, adjustable bookend that looks pretty hot. This shelf has an integrated bookend (a cube with an oversized wing-nut that you can loosen and slide on a track to make room for more books). The shelf is available in walnut, oak and beech. The Hold on Tight shelf is available for purchase, but there’s no price listed on the site, so you should just e-mail Colleen if you want one. – Via – Device