I like the idea of carrying a camera. I've heard you should carry a cheap disposable camera in case of a car crash so you can document the damage and positions. I like to get them for doing Army training. If I break or lose it, I'm not out much like I would be with my digital camera, but its fun to take pictures to remember what I've done. You can also use a camera for self-defense, to diffuse a situation before it gets violent. Taking a person's picture can be pretty intimidating. How many people have been caught on cellphone cameras and arrested? It can also be a good way to make friends; "Here's a picture of Joe, some guy I met on my walk during the earthquake of 2009. Right after this he gave me a coke."

A camera has a lot of good uses and a disposable one is light weight and less then $10. I know many people have cameras on their phones, but if you don't its a tool worth considering.

And if you must have another use, once you run out of film the flash could be used as a signal. The flash is really bright and disposable cameras will continue to flash after the films gone until the battery dies (a long time).