In Windows Live Photo Gallery, notice on the left-hand pane it now shows two tagging sections, one for the new “People tags” and another for “Descriptive tags” which already exists in the current version. Expanding the "people tags" section will show a list of people you have ever tagged in your collection of photos.

Similar to Facebook, you're now able to tag each person in your photos. What is different is that Photo Gallery will automatically detect faces in your photographs, allowing you to identify each person in the photos.

Google has already released “name tags” features in Picasa Web Albums.

Source:→ LiveSide