PicLens: Cinematic Views for the Web
I found that last week and I haven't seen any posts about it here. I thought I'd let everyone know.
It's a plugin for Safari and it will let you view images in a fullscreen-iPhoto type way. It works on Flickr, images.google, photobucket, facebook, yahoo image search and Ask.com Image Search.
When you have a list of images, like a search on images.google.com, you can click a small icon that appears and it will show you all the images fullscreen.