I like finding these little things. Modular, genius, and it solves a real problem. Obviously, it is a smoke alarm that fits on most lamp sockets. The bulb then screws into the device. Clean and easy. But there's more. The article also explains that it can power the bulb during a power failure. That is where I feel the design solves a real problem. You can probably relate to the idea of having an overhead light when there is no power.
viaYanko Design - Modern Industrial Design News