Since October, we've been working to make this process easier for you. First we added group tagging, so you could type one name and apply it to multiple photos of the same person. Now we're announcing tag suggestions, which will make tagging multiple photos even more convenient.
Because photos are such an important part of Facebook, we want to be sure you know exactly how tag suggestions work: When you or a friend upload new photos, we use face recognition software—similar to that found in many photo editing tools—to match your new photos to other photos you're tagged in. We group similar photos together and, whenever possible, suggest the name of the friend in the photos.
If for any reason you don't want your name to be suggested, you will be able to disable suggested tags in your Privacy Settings.