So by now I assume you've read the story about how big Everquest's economy was (is? eh...I don't know). Well here is the story of the economist who first discovered the financial size of the Everquest as compared to the real world.
[linky]
Castronova sat back in his chair in his cramped home office, and the weird enormity of his findings dawned on him. Many economists define their careers by studying a country. He had discovered one.
Brilliance sometimes comes in the ability to connect the banal with the ordinary and create epiphany.
Update: here's the research paper [linky].