Looks like there is an upcoming mobile boom for kids. NTT in japan offers the SA800i with build-in features from the techwear scene. One function is an alarm button that makes incredible noise. The loudness is like an compressed air hammer near to you.

Another function is "Imadoco" what means "where are you". It is like a location based service that tells parents where kids are. The phone sends emails even if it is off. This service is better then with usual mobiles because the UMTS network cells are more precise. However, there is a service like that for your current mobile too if you live in germany: http://www.trackyourkid.de/

[image from www.gadgetblog.it]