One of the features in uploading photos in Facebook is that users are able to tag their friends who are included in the image. However, the process of finding faces, tagging each one, and typing the names can be tedious.
Facebook felt their pain and they have eliminated some of the steps because the social networking site can now identify faces as soon as the users upload them, just like those face detection features on digicams. You still have to type the names that go with each face, though. Computers aren’t THAT smart yet.
Source: Facebook Blog, via Engadget