Tech innovators have yet to create a device that activates a personal defense shield to ward off would-be attackers. But a small gadget called Revolar can discreetly alert the cavalry.
A smartphone in hand means you can make an immediate call for help, but some dangerous situations leave no time to fumble with a phone. Its presence could escalate tensions. Even if you fire off a 911 call, the location info sent to dispatchers may not be specific, unless you are able to talk.
