Wikipedia
ยงI found a most excellent resource a couple of weeks ago: www.wikipedia.org
This is a very interesting project which is an open source encyclopaedia. For those who don't know what 'open source' means, it's basically where anyone can contribute. If you're a geek like me you should definitely check it out, you can find out all sorts of interesting stuff like...
Read about my home town - Toowoomba as contributed by someone (by the way for all you Toowoomba people, if something is incorrect you can correct it - that's the beauty of open source): http://en.wikipedia.org/wiki/Toowoomba
Find out all about basil: http://en.wikipedia.org/wiki/Basil
Find out all about Buster (or his bread at least): http://en.wikipedia.org/wiki/JackRussellTerrier
Find out the rules to billiards: http://en.wikipedia.org/wiki/Billiards
It goes on and on. This whole thing relies on the fact that there are so many people out there passionate and knowledgeable about their particular field of endeavour, and they are willing to contribute to such an ambitious project.
Have a look!