I just noticed that Yahoo has tweaked their advanced search page. You'll now see an new option that allows you to limit your query to material with a Creative Commons license. A Creative Commons "only" search interface is also available. Yahoo and Creative Commons announced a partnership in March. More in this post.
Save up to $400! Register now for SES New York 2012, the Leading Search & Social Marketing Event, taking place March 19-23. Google's Digital Marketing Evangelist Avinash Kaushik will keynote. Hurry, pre-agenda rate expires March 2!