Tom Warner is an atmospheric sciences Ph.D. student at the South Dakota School of Mines and Technology. His research area is lightening and associated
phenomena, and he has created a method for recording lightening. He uses a high-speed video camera that can record up to 54,000 fps. in a continous recording that goes to a looping memory buffer (when the buffer fills, it starts overwriting). When Warner sees lightening, he triggers the camera at the end of the flash, which causes the camera to save to real memory the preceding 2.5 seconds of video. That video is then transferred to Warner's computer for later analysis.
This video shows lightening striking near Devil’s Tower, Wyoming. You can read more here