I came across this wonderful book structure at work, not generally an environment where book structures other than codex flourish. The creator, my colleague Ricky Eyre, made it for a university assignment to collect and label New Zealand sea shells. Each different kind of shell is in a zip lock bag with the identifying information on a sheet of paper. Each bag is suspended from a heavy wire ring balanced on three hooked arms extending from a central stem and balanced on another wire ring base. The structure was Ricky's original idea and he and his dad welded it up together.
As a book structure it is extremely functional and well balanced. The 'pages' move easily on their 'spine' and the base is very stable even with all the weight of the bags being shifted about. Despite the utilitarian materials it's also attractive and eye catching, and perfectly suits the content and purpose.