...and it sat on a dusty shelf somewhere until someone bought it at a garage sale in 50 years?

This guy buys old cameras from junk stores and e-bay and the like. He buys the old cameras that still have someone's old exposed film in them—exposed forty, fifty, sixty years ago—and develops the film. What pictures he can salvage from these rolls of history he posts on the linked page.

I have looked through several sets of these images, but I will tell you a bit about my favourite series. He bought a box containing an old Argus (a camera company that started in my home town of Ann Arbor, coincidentally), and several rolls of undeveloped but exposed 35mm film. Upon developing said rolls of film, the saga of a soldier in World War II unfolded. It shows pictures of what look like training, time spent in England, Italy, and elsewhere in Europe, and a somewhat blurry yet affecting snapshot of a fellow soldier holding up a newspaper—"Peace at Last" reads the headline. The soldier returns home, taking a series of pictures of the Statue of Liberty looming closer and closer, and finally, pictures of family and friends, even his cat.