Where to find Creative Commons, Public Domain, and other "rights free" or "rights-implied" images.
Although geared towards finding images for use in Blackboard, this tutorial provides a good general overview on how to search for CC images in Flickr, and how to note the specific CC license and terms associated with a particular image.
Although a bit long, this tutorial does a good job demonstrating how to find reusable images using the advanced search feature of Google Image Search. Please note that you still have to evaluabe each image individually to verify the appropriate license. Get more information.
Microsoft Bing Image Search now supports the ability to filter your searches on public domain images or Creative Commons licensed images. From the Image Search Results screen, hover over the License menu to select a particular usage rights type.
Image courtesy of Microsoft Bing.