Social media for the 19th century
Public404.com is a website where users who are "in the know" can post content to the site and create their own pages. It is social media, social experiment and internet art all rolled into one.
There is a secret page where users can write web content (html, javascript and all) and have it appear on any page. Other users can post above, below, or even in the middle of posts. If you log in, you can moderate up to three pages with each account.