Surprised this hasn't been posted: click here . That page explains it. It also doesn't exist anywhere - the page is encoded entirely in its URL.

No idea how I'd use it, but damn clever

This is a cool idea that could possible be used in an alternative internet infrastructure.  Of course, it could be used for spamming too.

"Create a new site" doesn't seem to work in Safari.

I can think of numerous uses for this.