innerlogic

Google has recently added support for face based image searching.
There isn’t an option for using this service yet so you’ll need to add this parameter to the URL manually.

 Examples:

• gates (classic search)
• gates (using imgtype=face parameter)

 Compare the two queries. In the search results of the second example you also get this notification:

How to do this?
Simply make a standard image search and add the &imgtype=face parameter to the end of the URL on the results page:
http://images.google.com.au/images?svnum=10&hl=en&gbv=2&safe=off
&c2coff=1&q=gates&btnG=Search+Images&imgtype=face