Flickr: The Commons
Collaborative project between Flickr and the Library of Congress (and hopefully other institutions in the future) to share and tag public domain images. Currently 3000 images from the Library of Congress collection are available.
The Connected Classroom: A Lesson on Reflection: MORE Copyright Confusion...
A teacher's reflections on using images from Flickr. Although she encouraged the use of Creative Commons images, the nature of the student work clearly fell under fair use. Even so, she got complaints from photographers about the fair use of their work. She wrote a really thoughtful response to the Flickr users and had a great discussion with her students about copyright.