A non-linear cadavre exquis
The Internet is a giant mental network. In theory, it would be possible to create a miniature version of the web by creating one node with some content (an idea, a thought) and to ask people to create a branch off that node with a label of their own—based on what the initial node made them think about. People would keep on adding nodes, which would create interesting stories, like a non-linear cadavre exquis.