I heard of a bracelet-phone with a “panic button” of sorts that a child would wear around his wrist and would therefore be much less likely to get lost. In England they also have a “Teddyphone” which looks like a teddy bear and can only call about 4 pre-programmed numbers.
The sticker program IS a great idea, but like most knee-jerk reaction ideas, the details need to be hammered out.