Firefox has a neat little addon called Tilt that enables you to visualise any site in 3D. Look at Mashable. It's pretty cool. I'm sure it's also very useful for people who are in to that kind of thing. Apparently it's useful "when searching problems in the HTML structure (like finding unclosed DIV elements for example) by providing the extra third dimension, layering each node based on nesting in the DOM tree." I just think it looks cool.
Check out more in the video.