Google's photo management software, will be joining the ranks of other free Mac OS X apps:

If you've never tried Picasa before, it's a program that helps you manage, edit, and share your photo collection. It works especially well with Picasa Web Albums, Google's free photo-sharing site, so it can help you manage the photo albums you've shared online with friends and family as well as the photos on your computer. In addition to photo editing tools, the Picasa client includes features like automatic web sync, fast and simple sharing, collage making, and simple movie editing. And on the web side, Picasa Web Albums offers unique features like name tags, which help you automatically organize your photo collection based on the faces in each picture.

From the Google Mac Blog [googlemac.blogspot.com]