SepiaTown is a website that lets you view historical imagery of particular locations using Google maps.
If you have historical imagery, you can contribute to the project by uploading them to a particular location as well. Since the project is just getting started, finding historical imagery in smaller cities or towns may be difficult, but larger cities like San Francisco, London, Paris, or Moscow are filled with interesting photographs.
As the SepiaTown collection comes to encompass thousands of locations throughout the globe it will allow people to interact with history and geography in a new and exciting way; to tour the landscapes, cityscapes and events of history with a scope and breadth never before possible.
This type of “street view” historical imagery seems like something Google might want to integrate into their applications as well.