These can also be used without film to safely view a solar eclipse or other strong light source you don't want to view directly, and don't need a detailed image of. Simply take an index card and punch a small hole, and then use it to direct light from the sun to a piece of white paper.
A pinhole camera, however, does not do well for filmlessly viewing weak light sources such as a person or other object, simply because it works by blocking the vast majority of the light.