Music Meets Steganography
austad writes "Wired is running a story about how Aphex Twin has encoded a face into one of his songs. The face is visible when viewing the sound through a spectrograph. This is probably something I wouldn't want to see when coding in a dark room at 3AM. Sorry boys and girls, you have to buy the CD if you want to see it, encoding of the song into a lossy format destroys the image."
Find more info about the Aphex face, as well as some software to do same thing yourself
here.
Additionally, more information on it can be found here