Bookshelves. Plain old pieces of wood placed horizontally so that they intersect with equally mundane vertical pieces of wood? BOR-ing. Oh, sure, those were fine for pioneers and whatnot, but we're living in the 21st century, people... the age of rocketpacks! And miniature pet elephants! I think we can do a bit better.
First up, if all you German people want to ditch your reputation for being sensible and pragmatic, then stop coming up with such genius practical ideas, okay? Our Teutonic friends bring us these foldable shelves, which are brilliant, especially if you're one of those nomadic types who still likes to heft your books along with you when you move. If the Mongol hordes had had shelves like these, they probably would have been a lot better read and perhaps a bit less heavyhanded with the roving and pillaging.
Another variation on the invisible floating bookshelf concept is the Sticklebook, "the world's first invisible shelving system that creates the illusion of a line of books hanging unsupported on the wall." For the life of me, I cannot figure out how this thing works, and a close-up photo of the device, below, does very little to help me. I welcome your theories.
These Dryade shelves just make me happy. She looks like she's really enjoying that magazine. Much as I like this unit, though, it'd require reconfiguring our space, changing our colour scheme, and probably reprogramming our DNA to make it work. Try as I might, I just can't picture this comfortably ensconsed in our current "Victorian Modernist" aesthetic. But YM, as they say, MV.