A new DigitalPoint Forums thread is discussing a feature on Google Image Search that most people do not know about. Did you know you can restrict your searches of images to those that just return faces?
I did cover this news at Search Engine Land at the end of May based on a Google Operating System post.
To restrict your image searches by face only, append "&imgtype=face" to the end of the URL. Google should then show you a message that reads "Showing only images containing faces (show all images)." There is your confirmation that it works.
And it does work.
Test a search for q=rustybrick&imgtype=face versus just q=rustybrick. There is a clear difference.
Forum discussion at DigitalPoint Forums.