When was the last time you tested your smoke alarm(s)? Right, me too. And it’s not because we’re lazy (well, ok, it is) but it’s just so darn easy to forget those little life savers… until it’s too late. Hardwired detectors are great for us forgetful types, but if you're retrofitting, it can be a fairly invasive task, not to mention pricey. Another option, thanks to DuPont, is a Self-Charging Smoke Alarm that screws into your everyday ceiling-mounted light socket. The beauty in this is that the alarm automatically recharges itself every time you use the light, thus eliminating those pesky 9 volts and AA’s. Cost $34, go buy one now.