Creative Commons has a search engine (http://search.creativecommons.org) that allows you to search for media you can download and use in your presentations. Users can search Google, Yahoo, Flickr and other sites to find photos, music, videos and more that can be freely used in your presentations.
Presenters should be aware of BOTH their rights and responsibilities with respect to the copyright status of media materials used in their presentations. You can start with the US Copyright Office (http://www.copyright.gov) for more information on using copyrighted materials, but check with your own institution’s legal department if you’re unsure about a particular item you want to use.
In future posts I will add other sites for free media on the web.