The video function can be set to kick in the moment the pistol it is mounted on is unholstered. Additionally it can be configured to take a still shots during recoil (and presumably after the recoil). The primary purpose of the ShotCam is to document self defense shooting by civilians and law enforcement, but it would be great for hunting and plinking to show off your one-hit-wonder shots.
The device can be mounted on pistols, rifles or shotguns
Midway have it listed for $695.
Thanks to Heath for sending me the link.