Many modern technologies give the impression that they somehow work by magic, particularly when they operate automatically and their mechanisms are invisible. A technology called RFID (Radio Frequency Identification), which is relatively new, has exactly this characteristic. Librarians everywhere are closely watching RFID technology. Advances over using bar codes on library materials, RFID tags are being touted as a way to radically redesign how library materials are handled. But it is expensive. The tags are vulnerable to wear and tear and the technology is not fully developed. It's unclear...