My favorite feature of Picasa was duplicate image detection. IIRC, it would actually find duplicate images by the visual of the image and not just the bits. So

My favorite feature of Picasa was duplicate image detection. IIRC, it would actually find duplicate images by the visual of the image and not just the bits. So it could match smaller versions of the same image. This helped me clean up countless duplicate copies of photos all over my different disk stores.