Historypin isn't a new map exactly but this week's release of some exciting new features is enough to make it my favourite map of the week.
There is a new Historypin mobile app. The mobile app and the desktop version have a new augmented reality view in Street View that dispays thumbnails of nearby photographs. If you click on one of the photographs you are immediately transported to that photo superimposed on the present day view in Street View.
Even more excitingly you can now view historical video clips superimposed on Street View. For example you can watch a 1903 film of the opening of the Williamsburg Bridge in New York superimposed over the Street View of the bridge.
Another great new feature is the ability to create your own tours. You could create a tour of photographs of San Francisco taken before the 1906 earthquake. Alternatively take a tour created by others. For example this tour of photographs of Gandhi's visit to Britain in 1931.