Google has introduced Find My Face, a Google+ photo tagging feature that "learns" to recognize who your friends and family are.
By manually tagging and identifying different people in your photos on Google+, the software will over time automatically identify who's who in a given photo without any extra effort on your part.
Once you've been at it for a while and have had Google build a database of who's in which photos, you can sort your photos by who's in them.
Find My Face is turned off by default. Look at a picture with someone's face in it and Google+ will ask you if you want to turn it on.
It will automatically identify where a face is by drawing a circle around it. Click inside the circle to tag the person.
Type their name and select it from the list that appears.
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