Here's an idea perfect for the family historian-slash-photographer.
The idea was to revisit historic photograph locations and take identical photographs, as if the camera never moved and the world changed around it. It's a little more difficult than I expected due to variations in lenses, inaccessibility of locations and a lack of constant markers. Still all of these are close to correct (some are better than others). [Link, via Neatorama]Click on a link, then move the slider to segue from past to present.