Google has just announced the latest version of Picasa, its free photo-editing software for Macs and PCs. What's great about this new version is that it can scan your photo collections and create groups of similar faces (similar to Picasa Web Albums and iPhoto). All you have to do is add a name tag to a set of faces (if you're signed into Gmail, it will auto-complete names as you start typing), and then Picasa will suggest pictures that it thinks match faces in your albums and put those into the appropriate "people" groups.
To learn more about Picasa 3.5, and to see a demo video of it in action, just read more.
Picasa also uses Google Maps to make geotagging quick and easy (so you don't need to install Google Earth to do so anymore). Just choose your pictures, click the Places panel, find the place you want to geotag, and drop the pin on the map. Once all your pins are in place, you can look at an entire group of photos on a map to see where they were taken. Keep in mind your geotags will sync with your Picasa Web Albums, so you don't have to worry about having to geotag your photos again. You can download the latest version of Picasa from here.