It took a whole year, but Google is finally adding the facial recognition features you can find in Picasa Web albums to its desktop app. With today’s release of Picasa 3.5, when you add a name tag, it scans your entire photo library and applies that name to every match. If it’s not sure it’s the same face, it gives you the option to apply the tag.

To help you tag people, Picasa auto-completes names from your Google contacts when you start typing a name. And you can also geo-tag a photo by marking a photo on Google Maps.

Once faces are tagged, you can create a face collage of the same person, time-lapse movies, or sync the tags with your Picasa Web albums. You can now upload directly from your camera to Picasa Web albums if you like. Also, with this release the Mac version is no longer in beta.

Facial recognition is now a standard feature for photo apps, both desktop and online. iPhoto has it, Faceboopk Photos has it (through Face.com), and now both Picasa’s online and desktop versions have it.

Here’s a video with a demo of the new features: