Disney Research and Carnegie Mellon University have developed a way to use RFID tags to make interactive games and controllers so cheap, they're "essentially disposable." Their system called "RapID" can sense if you're moving or touching objects attached with cheap, battery-less RFID tags in near real time. RFID readers typically take up to two seconds to read tags on luggage or other items, but RapID can recognize movements in as little as 200 milliseconds.
The team made a bunch of interactive toys to demonstrate the system's capabilities, including a tic-tac-toe board that displays the game on a computer screen and plays sound effects. They also made a physical audio control board you can use to mix music and a toy spaceship whose movements are animated on screen.
Since you can slap a cheap RFID tag on pretty much anything, the system can even be used to create interactive storybooks. As Disney Research scientist Alanson Sample said, "By making it easy to add RFID-based sensing to objects, RapID enables the design of new, custom interactive devices with a very fast development cycle." The team demonstrated all the toys we've mentioned above (and more) in the video below.