We've recently partnered with polarrose.com to allow you to identify people in your photos. We will make a more detailed announcement soon, but in the meantime, feel free to start identifying faces in your photos and explore polarrose.com.
Polar Rose has created a great facial identification/recognition system that analyzes your photos and locates faces. Users can then assign names to the faces, and those names will then be searchable on polarrose.com.
The Polar Rose widget is currently only active on public albums, and it takes a few minutes after you first view a new album for the toolbar to pop up at the bottom of the screen. But once it does, just click the "name the people in these photos" button to get started.