Picasa Web Albums has a new zoom spectator that uses Flash. If you click on the magnifying glass icon next to a photo, you can select a rectangular area from the image and zoom in or zoom out. The quality is called "microscope zoom" and it doesn't fall back to the old account for users who haven't installed Adobe's Flash plugin.
Another new characteristic lets you view all the EXIF tags that are available by clicking on "full details page". You'll find a lot of tags that offer more information about white balance, orientation, exposure, color space, brightness, light source and more.