It might seem like an annoying idea, but its also quite a practical one. This eco friendly lamp will turn off every time you blink. Randy Sarafan created this handy lamp that turns off automatically whenever you close your eyes.
It takes the idea of using motion sensors to automatically turn off lights one step further. Except, if you like having electrodes and wires attached to your face for the sensors to work.
Sarafan also happens to be the technology editor over at Instructables, and he's created a step by step guide on how to build your own blink lamp. [Instructables via Treehugger]