Bookends come in all shapes and sizes. Some of our faves include the Portal Bookends, Mr. ED Bookends and the Falling Bookends. Well, we’ve now got another one to add to the list, the Hold On Tight Shelf. Unfortunately, the shelf is a concept only, but with the attention it’s getting we’re hoping it will become a reality. That said, built into the shelf is a powder coated aluminum block that slides along a track allowing you to secure a small or large number of books. The block tightens into place using a wingnut below the shelf. It’s designed by Colleen Whiteley and measures 41″ long by 8″ wide by 11″ high.