Everyone has heard of Flickr, but are you using it in your classroom? Look for CreativeCommons. It you are searching for a photo of a place, Flickr is often better than a search engine. There are so many different ways this amazing resource can be used in a classroom. It's always the first site I look at when starting a geography/history/current affairs lesson, as there are very few places on this planet where a tourist hasn't been and snapped.