Just watched an episode of "I Shouldn't Be Alive" last week in which a young couple who had gotten separated from their hiking group and were lost with no supplies other than a point-and-shoot camera found a cave. The woman was reluctant to enter the cave in case it was already occupied (e.g. a bear or other large predator), so the man used her digital camera to take a flash picture of the inside of the cave. That's one survival use of a camera.

They apparently never considered trying to use the camera lens or batteries to start a fire, though.