It's tough, these days, to not "take" images off the Internet that are copyrighted. Photo Pin solves that dilemma. Just go to Photo Pin and search their image database using keywords. All the photos are from Flickr, yet have a Creative Commons license that gives you permission to use the image and not violate copyright regulations (you just need to credit the image source).
Using Photo Pin would be a great lesson for our preK-16 students - how to use images that do not violate copyright (not to mention, great lessons on Creative Commons licensing, citing sources, selecting appropriate images, etc.).
Enjoy!
Jen
