I agree, it's pretty incredible. There are other programs like it with face recognition, but from what I've heard it outshines the others in how easy it is to tag people. Apparently that part is fairly difficult with other programs.

But I've had the same experience as you. It found photos of me with and without sunglasses, with no facial hair, with a goatee, with a full beard, and even in four or five different Halloween costumes.

It certainly has trouble as it gets the outlying photos that are particularly difficult to identify, but at least it's quite easy to do manually. The only other time I've found that it's slightly inaccurate is actually pretty amusing. For example, particularly at first it frequently confused my wife for her brother and the other way around. It also confuses her two cousins constantly. It often confuses family members, basically.

Now, I'm not sure you've played with it enough yet, but there's one seriously cool advantage to having this facial recognition. Once you have most of your photos tagged, try the following:

- on the bottom-right of the Picasa window, click the "Show/Hide People Panel" button (it looks like a head and shoulders)
- click on your own album under "People" on the left, so that you're seeing all the photos of you
- looking back to the panel on the right, it shows you all the people who appear in photos with you
- now, one by one, you can click on each person and the center view will change to only show photos with yourself and the people you've selected

You can do this with anyone's face album, of course. It's great when you say "I wonder what photos I have with myself and those two friends of mine." It's seriously cool.

I'm glad you've discovered Picasa again. I'm a huge fan of the application.

*edit*

ps- "having bear" is the strangest Italian expression I've ever heard