Self-charging Smoke alarm

Dupont are famous for Teflon and chemical coating, but rarely electronics. This one's a great one to add to your list. Dupont's self-charging smoke alarm makes it easier to stay safe. You just screw it into a light socket, then screw a lightbulb into the alarm. Whenever the light is on, the unit charges, and it'll operate for 30 days at full-power. Reasonable price of $30 for not getting your house burnt down.