Flickr Creative Commons- A great place for teachers to find images.
Note: Creative Commons is NOT a safe search tool for students. Although Flickr has a set of Community Guidelines for posting images, there are some images that could be considered inappropriate for school. Advanced search tools have a "safe" search option, but this option is not as "safe" as educators might like it to be.
"Creative Commons gives tools to the creator to make a choice about
copyright." Watch this short movie to see the spirit of Creative Commons. All Creative Commons images are shared various CC licenses. You can read about the licensing at http://www.flickr.com/creativecommons/.