On a tech-heavy paintball forum I frequent there is a guy that mounted a camera to his scope to get crosshair footage using First Strike paintball rounds footage in action. I must say, the effect is pretty awesome! I'd love to see some of the bolt-turners on this forum do the same. Not only is it different than the usual gun camera footage but it highlights the mistakes people make on the field and let you know how you look to the other side!
How he did it:
"You'll need the following parts to build your home made scope cam.
1. Your old digital point and shoot camera.
2. Flex pipe
3. PVC pipe
4. Dremel Tool
Dremel the blue electrical box until it fits your camera. Cut a hole in the box for the lense. Glue pipe in front of the box and using the flex pipe attach to your scope just like in video"

Video installing the cam (go to 0:44):