Last Wednesday Google announced photo tours, a feature of Google Maps that guides you through a 3D photo scene.
Photo tours are available for more than 15,000 popular sites around the world, from famous landmarks such as St. Mark’s Basilica in Italy to scenic treasures like Half Dome in Yosemite. They can be initiated from Google Maps in two ways. First, when you search for a place, such as Trevi Fountain, the results in the left panel will indicate if there is a photo tour available: click either the thumbnail image or the link to start the tour. Alternatively, if you’re browsing the map and click on the label for a particular landmark, the info window that appears will indicate if a photo tour is available.
Read Google’s announcement here: http://google-latlong.blogspot.ca/2012/04/visit-global-landmarks-with-photo-tours.html
See the new tool in action at http://maps.google.com/maps?hq=http://maps.google.com/help/maps/phototours/mapleft.xml&h=1100