Since GPS implants aren't yet available/socially acceptable, it looks like your best option for tracking your rambunctious little child is the Ion Kids tracking system. It consists of two parts: first is the wristband that locks (locks!) onto the wrist of your child, second is the tracking unit. The point of the device is to be able to tell if your kids leave the yard, and if they hide under the sink after one of your drunken rages you can also use the "find" button to locate them. Furthermore, if it detects that it isn't touching a child's skin anymore it'll let you know that little Madison or Ethan or whatever you named your poor kid has been smashing at his parole bracelet with a rock. Now that's peace of mind! It's available now for a mere $300. — Adam Frucci

Ion Kids, via Shiny Shiny