I used a similar circuit for an Intel 8749 Micro-Bot project I wrote for Circuit Cellar way back
in 1998, issue #92, to turn on a set of bright LED headlights on my robot.

Worked really well. Robot entered a dark area, and headlights turned on automatically.

Moved into the light, headlights turned off.

http://www.circuitcellar.com/archive...ents/1998.html

Déjà vu ehh...;o)