it uses two small batteries and two green LED's. it very quick, cheap and easy to make; it only took me about 5 minutes to build when i had never built one before! it only cost about £5 to make!
I'm planning on making this on ebetter quality with a switch and a better stand (also less tape!)
If you like please vote for me in the i made it photo contest.
Instructable coming soon!
(you can't see the LED's in the head).