The badge for Defcon 17

The badge for hacker conference Defcon 17, held over the weekend in Las Vegas, was the most sophisticated yet. Developed by Joe "Kingpin" Grand, the front features multiple layers of silk-screen graphics. Each type of badge for the various participants (this is a press badge) is shaped differently so that when they are assembled together they form an image. The badge has a built-in microphone, and an LED reacts to sound by flashing, changing colors, and even blinking messages in Morse code.