Flash guru Michael Battle has created a 3D version of Digg. You can zoom around all the popular stories on Digg's technology page using your mouse and scroll wheel. It's not exactly the most useful interface, but it's a ton of fun and it's very slick. If you get lost, just refresh your browser. There's also a complete list of advanced navigation instructions here.
Seeing Web sites in 3D reminded me of the 1995 movie Hackers, where a young Jesse Bradford hacks into a complex computer network by flying around a magical city of what can only be Microsoft Excel spreadsheets (clip here).