V.ALRT is a personal alert device, a button you carry with you that pairs with your iPhone (iOS 7 or later) or Android phone (Android 4.3 or later). When you press the button on the device, V.ALRT will automatically dial or text message to three pre-selected contacts, sending your current location along with a canned message (such as “I’ve been in an accident”).

There are obvious concerns here, such as accidental button presses. But I found the V.ALRT to be an interesting idea. The current price is US$59.99 with free shipping.