Wikipedia, I notice, is now linked to by blogs and sites all the time. While I have known about it for a long time, it was first thrust at me when someone noticed I didn't know what or who "Sith" was. Ever since, I have used it often. (Not found "Sthay" yet, though).
But I'm coming to believe that it is most useful, even fascinating, for what you learn about the world from its very character -- a freely editable work -- and the way its entries change over time. I've watched a few threads like this now, and it's always enlightening.
An example, you asked? Here's one, I've had to do some digging to find this, as you will see.
About a month ago, I looked in Wikipedia for an entry about the 1993 bomb blasts in Bombay. I found one. Stored on answers.com (have to show you this because the entry has changed on Wikipedia), this is what it looked like.
Note the second sentence, which reads: The attacks were the worst wave of criminal violence in that country's history.
Hmm, I thought idly, the "worst wave of criminal violence"? But wait.
Last week, I looked at the same page again. Here's a Google cache of it as it appeared then.
Note the second sentence, which reads: The attacks were the worst bomb explosions in the country's history; various outbreaks of widespread criminal rioting (examples: 1984 Anti-Sikh riots, 1992-93 riots after the destruction of the Babri mosque in Ayodhya, 2002 Gujarat violence) have killed more Indians than these bombs did.
Hmm, I thought idly again, that's an interesting change, now more accurate.
But clearly somebody didn't like this change much. Because when I looked this morning at the entry, here's what the second sentence looked like: The attacks were the worst bomb explosions in the country's history.
As I said, fascinating. Make your own inferences, if you will.