Microsoft is developing a new API project called poject "Oxford," and it includes face, speech, and more "smart" API technology. Despite being Microsoft, I actually found this to be very useful. ;)
Here is a video about the face recognition, and it's very interesting.
You can try out that service here. They also made a Twins or Not? website utilizing the same technology. For more information on Project Oxford, visit Microsoft's special website. I'm sure Google will expand on this technology even more if Microsoft gets a little less ignorant with hiding source code.
C|H of C3