The process you're referring to with the flashlight is called "light painting" and has become quite popular. There are other uses, as well.
CocoaRoger wrote:
good idea thanks, meanwhile on this show they are shooting a waterfall at night. Something I would never have thought of doing. He wants to illuminate the fall yet get stars in the background so he set his ISO 1600, F stop 4 and a twenty second exposure but then he took a flashlight and shined it up and down and around the waterfall so the exposure gives him a almost glowing waterfall while still seeing the stars in the sky. Heck of an idea.