Forget mace and weapons, the Japanese are too hardcore for those types of crime prevention. Instead, they are rolling this out. It's a handheld device that can do multiple things to ensure your Swap Meet Louis will stay safe. It can dial out two preset numbers and also be able to receive calls. On top of that it can act as a GPS device along with an integrated alarm. A panic button will sound a loud alarm and there is also the option to transmit location information without the alarm going off. This device will require a monthly fee of 1720 yen, or roughly $14, and is Japan-only folks, sorry.
Japan launches more crime prevention phone devices [Phoneyworld]