I recently got a Contour GPS camera and had the chance to take it underground.
Mounted on my helmet and using a spark st-6(large spot/flood) and sd-6(pure flood) for lighting and I had excellent results. The lighting combo filled almost the entire viewing area and wasn't too much as to white out the pic. Video was crisp and clear as well as the sound. Ill post a video after editing it down some.
Two thumbs up!