Dear Photograph popped up on which people matched up old photos they had taken with the current-day location. The differences were often exciting and resonated emotionally with readers.
FILMography is a similar blog that follows the same premise – but with stills from movies. The author appears to be based in New York City, so most of his match-ups are from iconic scenes set in the Big Apple, but he appears to have taken a few pictures from foreign locales as well.
In any event, the blog is worth a look-through. It's surprising how many landmarks, building facades, and details are still the same as they were in the 1950s.