So, USAPhotoMaps is a smart and powerful application that downloads U.S.Geological Survey aerial photos / topos from http://terraserver-usa.com/ (available at no charge, courtesy of Microsoft) and creates a map from them. To download aerial photos, select File -Download Map Data -Fill Screen (or press the 'F' key). When the screen has filled with photos, you've begun your map! To enlarge it, zoom out and/or scroll the map. Then select File -Download Map Data -Fill Screen again. 1 meter/pixel photos will be downloaded if the Zoom level is 1 thru zoomed-to-8. 8 meters/pixel photos will be downloaded if the Zoom level is 8 thru 64. Photo/topo data is saved on your computer's hard drive after each row is downloaded.