The Ring (I'd use it more than a handgun lock)
I saw a nifty safety lock for handguns on a tv program. The hand gun is equipped with some sort of locking mechanism which is unlocked by the presence of a magnetic ring which is worn by the owner. No ring, no discharge, no accidental shootings. Great idea, no doubt it'll save lives, make the world a safer place, etc. But what I could really use is a ring that would unlock, and start my car when I lose my keys, or prevent my car starting if someone tries to start it with out the ring.