In marching band one year, one of our special effects was a "twinkling" across the field, using what we jokingly referred to as Flash Bangs. They were little boxes with chemicals inside (I think) that when you pressed a button, they emitted a single, very bright, very fast flash of light. After that they had to be thrown away. Almost reminded me of fireworks, but they were safe enough to be used right next to our faces. Anyone know of anything like that?