DD is 8 and going off on a couple of trips on in the next month - school,holiday club things. I bought a wristband that allows you to record your details in the unlikely event she gets lost. Maybe over the top but....;
DH suggested that all children should get chipped instead (like animals?). His view is that if children are lost or abducted, then they would be easier to track down. I see flaws in this - basic human rights stuff - but can see some advantages. I said I would put it to the MN Jury!