Alan asked me about RFID, which stands for Radio Frequency Identification. An RFID tag is a small object, sometimes a sticker, that is attached to a book, video, CD, or even a beer keg. Mobil SpeedPass and EZ Pass use RFID. Stores often use them for inventory control. Some libraries use them instead of barcodes because several items can be checked out simultaneously just by placing them on the RFID reader.

The ALA web site has an article describing how RFID works, as well as its advantages and disadvantages.