Lest you think RFID is the only technology being used in Japan to track kids, Fujitsu is testing a system that can store detailed data in QR Codes, eliminating the need for kids to wear or carry a digital device. The system works sort of like a CueCat for kids; if a child is lost, his QR Code can be read by an Internet-enabled scanner, which can automatically forward the child's information to a specified server, which will in turn notify the parents. Unlike RFID, of course, there's no active transmissions being sent by the child, but the QR-based system has the advantage of being cheap to implement. Of course, the same results could probably be achieved by having the child carry a wallet-sized card with his home address and phone number, or a camp-style tag sewn into a shirt. But, then, Fujitsu wouldn't be able to sell any scanners, would they?