A great idea is the map mashup LookBackMaps. The service mashes up to data maps with historic photos to have a look to the former appearance of places worldwide. The site is a project with an ongoing development with a lot to do regarding available historic photographies. Current information about the service is available by registration, blogs and newsletter. Too, who wants to contribute photos is welcome to participate at LookBackMaps.

Directory Sources: Photography – Online Maps, Route Planning