Pics4Learning.com
http://www.pics4learning.com
“Copyright-friendly images for education.” Excellent website for kids. The pictures are all categorized by topics. There are lots of lesson ideas that would work well with digital storytelling. You can also add your own photos to the website as well.
Library of Congress American Memory Museum
http://memory.loc.gov/ammem/index.html
This Library of Congress has great primary sources for you to use in your projects. Remember just because it is on a government website doesn’t mean it’s necessarily public domain. However, abiding by Fair Use guidelines, students should be able to use these resources.
National Archives
http://www.archives.gov/research/arc
Tons of photos here, more than you could ever imagine–and the number of digital resources is constatnly growing.
Discovery School
This site is geared towards educators and students, with free material that is intended to be used for school projects.