Ogo-Sangyo Co. of Japan has begun shipping school uniform blazers outfitted with Global Positioning System (GPS) receivers, which enable parents to monitor a child's location using their PCs. Further, the blazer contains a "panic button" that will summon a security person if the child gets into trouble.
Speaking as a parent, I like this idea a lot. But kids--particularly older kids--are unlikely to stand for this level of oversight. I foresee a thriving business in "mules" who are paid to wear a student's jacket and frequent "acceptable" places (museums, libraries, temples) while the jacket's owner heads off to the dicier and more entertaining parts of town. (You'll be able to spot mules because they'll often be wearing more than one jacket at a time.)
However (and speaking as someone who was firmly in the "bullied" camp when he was growing up), I think the panic switch sounds pretty darned cool, especially for younger kids. What six-year-old boy wouldn't want to be able to summon his own personal Terminator with the touch of a button? (Read Accenture Technology Labs' take on Sensor Telemetry.)