Yes! iPhoto 09 is pretty amazing. It goes through your collection and scans everyones faces (takes a few hours though with my 3,000 large pictures over wifi). It groups people who have the same face together in a new 'faces' part of iPhoto, and you can name the faces. It automatically tags people once it knows what they look like, on new photos. It even uploads to facebook and includes the tags on there, which is going to save me a ton of time!
Also has map for geotagged pictures, however I never take photos on my iPhone so don't take advantage of this.
