The IonKids system from the firm Bluespan allows parents to give their young children some autonomy in the context of their environment to a certain point. The child wears an aesthetically pleasing Wristag that has the capability of communicating with a PDA-like Base Unit that would be near a caregiver. If the child wanders too far away, the wireless communication kicks in and the Wristag sends an alert to the screen portion of the Base Unit and the parent can effectively locate the child's position. It seems like this product is quite an upgrade to silver bells on the shoes.
Via: Coolhunter, Kits start from $199, you can order from here.