Here is a smart piece of jewelry that can get you help when you are in trouble. The CARRAT Smart Bracelet is available in 18k gold and 925 silver. It combines with your phone for GPS tracking and emergency phone calls. When pressed, the device activates and emergency call to your main contact. It also sends a text to your other contacts with your exact location.
CARRAT has an app that lets you configure up to 5 safety contacts. It also lets you configure the automatic emergency message. This project is currently getting funding on Kickstarter. You can find out more about it here.