It may be a solution in need of a problem, still an interesting use of inflatable mechanisms -
The ABRACADABRA bookmark aims to make finding where you left off and opening to that page easier. I didn’t know it was an issue but now I hate my ordinary paper bookmark. The ABRACADABRA contains an air-filled chamber, half of which is flattened by the weight of a book. Squeezing the exposed side inflates the concealed side lift the page just enough for your finger to slip in.
Though only a design concept, I’m guessing real-world use might warrant a longer ‘concealed’ half in order to stay put without slippage.
ABRACADABRA Puffy Bookmark[via]
HOW TO – Make a wooden bookmark on CRAFT:Blog