A photographer friend of mine brought Strikemark’s range of digtial camera mounts to my attention. They have mounts for standard digital cameras (via. the universal tripod mounting system build into most cameras), GoPro cameras and Contour digital video cameras.
Mounting one forward and one backwards would add some balance to the rifle as well as capturing more of the action.
What the company should make is a stereoscopic mount. 3D range videos would be nifty.
The standard camera mount is $35. The other mounts range in price from $30 to $50. They ship worldwide.
[ Many thanks to Bryan Jones for the tip. ]