We've previously featured the clever gadgets of Kipkay, including his DIY Laser Pointer, his DIY Star Trek Phaser, and his Potato Gatling Gun. One of his latest projects was a slingshot with a laser sighting system. He used a 6 mm laser diode powered by two AA batteries. At the link, you can watch a video showing how Kipkay built it.
Video Link (self-starting) via DVICE | Screenshot: DVICE