If you have a teenager at home, this might be the answer to your prayers. Called PocketFinder, it's about the size of a cookie. You can dump into your kid's backpack and then track him or her on the internet in real time. Per The New York Times:
PocketFinder lets you designate safety zones and danger zones, and alerts you if the device enters or leaves such areas. It can also track how fast the device is moving and notify you if a preset speed limit is exceeded (parents of teenage drivers, take note).
Big technological breakthrough... Or big brother (big mother?)?