I used to have a NovaDreamer induction device (http://www.lucidity.com/novadreamer.html). Ironically, I was never able to attain lucidity while using one. It's a mask that watches for eye movements (such as those during REM sleep), then turns on leds inside the mask. You're supposed to use bright lights as a reality check during the day - if you see a bright light, perform a test to see if you are dreaming. Hopefully, the led light will be incorporated into your dream as external stimuli sometimes are, and you will hopefully have the habit down of doing a reality check which will fail and you'll realize you're dreaming.