TiltViewer

Airtight Interactive (makers of SimpleViewer), have a really great Flickr browser (photos are pulled from the Interesting) with lots of eyecandy called TiltViewer.

While it's definitely a very cool Flash application, I don't think it's going to revolutionize the way we look at photos, especially because most photos do not require that you look at them any other way but straight on. However, I could see Apple coming out with an extension to iPhoto which uses Core Graphics to do some sort of photo browser, or perhaps it'd fit better into Front Row. I think this is doubtful.