Thanks Mike for pointing me towards this Arstechnica article about the new facial recognition in Google Image Search. If you add
&imgtype=face to any image search url it will only show you faces. Try this search for Cork, Ireland and compare it with this facial search for the same terms. Scary eh?
Ordinary image search
Facial image search
PS. That 4th picture on the facial search is mine. This should make finding images a lot more interesting.