Tagberry is a wiki that is attempting to map the world using hyperlinks. Every entry on Tagberry is simply a list of links. It functions like a stripped-down Wikipedia or everything2. For example, under the tag "fell off a horse" there is a list of people who have famously done so: Christopher Reeve, Madonna, Prince Charles, Paris Hilton, Roy Kinnear, Ghengis Khan and William the Conqueror. And each of these names is a link.
It's a handy way of getting a snapshot of what something "means" - where the meaning is the sum of the tags. So, users have tagged Pete Doherty, the lead singer of The Libertines, as meaning: mediocre, Kate Moss, smack, crack, narcissist, car crash waiting to happen, sweaty, wears heart on sleeve, fond of wearing hats, led his woman astray, thinks self a bit arty, face too big. So that's Pete Doherty in a nutshell.
Tagberry uses Mediawiki, a free wiki software package, (a spin-off from the Wikipedia software). It's open to anyone to post on it, but you have to register first (which is free).