Inflatable book-mark

Designers Jung-Hyun Lee, Won-Sik Chae and Rhea Jeong have prototyped this "Abracadabra" bookmark that uses a little air-filled bladder to lift the page at the right spot. I think it'd fall out if placed at the page side, as shown here, but it would work pretty well if placed at the spine, in the crease of the binding.