The most useful aerial photo resource on the web, and one that will undoubtedly be of use to many. Users have the ability to search by location and retrieve black and white aerial photograpy, black and white de-classified Russian sattelite imagery, and color topographic maps from the US Geological Survey. Viewers can get quite good scale, but there is little additional information to help you locate a site. Some enlightened state and local governments have a policy of giving away aerial photography that is produced with public money. Massachusettes is one such state.
Users can browse the archives of images previously captured for other customers.
A clearinghouse of vendors selling aerial photography and other remote sensing imagery. You may be able to get a thumbnail-size image for free, but this site is there to sell you data, not give it away. Most of the data is very small-scale. Three sites describing nationwide aerial photography programs under the direction of the US Geological Survey. The USDA is responsible for thousands of flyovers throughout the US dating back to the 1930s.