When you first read the name “Picasa” you’re probably thinking, that it’s a typo or something. However Picasa is a new google program (which they accuired, not created themselves) for organizing your images. I’ve tried it and must say, it works really nice and fast, as you can expect from google. I previously used ACDSee, but this, I think comes really close.
Have a look yourself: http://www.picasa.com/google/.
Ow BTW it is free 😀