An Israeli company has developed
CD-ROMs which cannot be copied. The CDs contain a smart card with a photodetector and LED and a chip containing a decryption key; to decrypt itself, the software requests the key from the card.
Though I'm skeptical about the practicality of such a system; CD-ROM drives are read-only devices, and whether or not the software can control the laser enough to communicate with the chip (to send requests for codes) seems rather uncertain, given that it's not part of any standard that drives have to comply with.