Here is a neat little article I read from RFID Journal, Tags for CDs Get a Boost.

All to often libraries find that their CDs have walked away. So in order to prevent theft, some libraries shelve the jewel case and patrons go to the desk with empty jewel case to get the CD. This can make the check out process kind of slow, and really limits people's abilities to browse through something like a music CD.

According to this article a company has come up with a way to attach an RFID chip to the CD and boost its strength so that it is 100% readable from the RFID scanners. The chips do not interfere with computers or cd players and inexpensive to buy.

Another use of RFIDs is to manage the whole library collection. The Vatican is using the RFID chips (not for CDs) to track and manage their vast collection. They 1.6 million volumes and over 30 miles of shelving.