When talking to teachers about the importance of using copyright free media in work they intend to distribute outside their classroom walls, I am often asked for a list of sources.
The easiest thing to show people is how to use Advanced Image Search on Google. Click on Advanced Image Search to the right of the search box. On the page you get, look for Usage rights and choose to search for images that are labeled for reuse.
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There are lots of places to find free copyright-free photos and images. Here are a few sources I've collected:
Sources of free copy-right free photos:
http://commons.wikimedia.org/wiki/Main_Page
http://www.flickr.com/creativecommons/
http://www.loc.gov/pictures/
http://search.usa.gov/images?locale=en&m=false
http://smithsonianimages.si.edu/siphoto/siphoto.portal?_nfpb=true&_pageLabel=home
http://www.morguefile.com/archive/
http://pics4learning.com/
http://www.photos8.com/
Sources of free copyright-free clip art:
http://www.lakeshorelearning.com/general_content/free_resources/clipArt.jsp
http://www.phillipmartin.info/clipart/homepage.htm
http://office.microsoft.com/en-us/images/
http://etc.usf.edu/clipart/
http://www.school-clip-art.com/
Discovery Education also has about 1200 clip art images you may use if your school has a subscription. They can be found in the left-hand side Navigation Bar under Media Type. Press on More and find Clip Art in the list.
http://commons.wikimedia.org/wiki/Main_Page
http://www.flickr.com/creativecommons/
http://www.loc.gov/pictures/
http://search.usa.gov/images?locale=en&m=false
http://smithsonianimages.si.edu/siphoto/siphoto.portal?_nfpb=true&_pageLabel=home
http://www.morguefile.com/archive/
http://pics4learning.com/
http://www.photos8.com/
Sources of free copyright-free clip art:
http://www.lakeshorelearning.com/general_content/free_resources/clipArt.jsp
http://www.phillipmartin.info/clipart/homepage.htm
http://office.microsoft.com/en-us/images/
http://etc.usf.edu/clipart/
http://www.school-clip-art.com/
Discovery Education also has about 1200 clip art images you may use if your school has a subscription. They can be found in the left-hand side Navigation Bar under Media Type. Press on More and find Clip Art in the list.
Please keep in mind that while many images are free to use, the creator/photographer may still require attribution under the Creative Commons license. If this is the case, it is my understanding that supplying the URL under the picture on the page satisfies this requirement.