Even with the shift to RFID tags, many libraries still use barcodes. A good many of the libraries using RFID use both the tags and the barcodes.
We're all familiar with the technology; a laser passes over the code and reads it through measurement of reflected light.
A new technology in coded information utilizes something similar but in reverse. Called a Bokode, it uses a small LED covered by a lens with dark patches on it. To read it, you need a camera and some software. The dark patches detail the data and the data given out varies with angle. In other words, a Bokode on a book right in front of you might tell you an item number and title with brief synapsis. A Bokode on a book a little farther down (taken with the same camera at the same time) might tell you why you might like this book if you're interested in that one.
But for my money, here's what makes my little Circulation Supervisor brain titter with glee:
"Let's say you're standing in a library with 20 shelves in front of you and thousands of books."
"You could take a picture and you'd immediately know where the book you're looking for is."
More from the BBC.