Pics4Learning: Pics4Learning is a safe, free image library for education. Teachers and students can use the copyright-friendly photos & images for classrooms, multimedia projects, websites, videos, portfolios, or any projects in an educational setting.
A Community-Indexed Photo Archive: The images and photos found in this archive come from three main sources: the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and the U.S. Fish and Wildlife Service (FWS). Each of these sites clearly state that their photos and images are in the public domain and give the conditions for their use.
Free Foto: FreeFoto.com is the largest collection of free photographs on the Internet (link back and attribution required). See FREE USE RULES. The comprehensive, yet easy to navigate site, offers images that are free for on-line use, with higher quality versions available for sale.