Memex
The "Memex" was an imaginary machine discussed in a famous article called "As We May Think" written by an American scientist called Vannevar Bush in 1945. In many ways it foresaw and even inspired the invention of the web.
He imagined a machine that contained all your information. Everything would be easily accessible. You could write little notes in the margins of things and string things together to express some knowledge. These were called "associative trails" and the idea was that you could share them. Other people could insert them into their own Memex, and then they could explore that knowledge too.
He saw them as tools for thought, maybe in particular, collective thought.
As many people have pointed out (e.g. [1]), in lots of ways, we're still catching up with this vision.
See also Artificial Intelligence and Related Pages.
