Real money virtual estate

Perhaps you've heard of the land baroness named Anshe Chung. No? Maybe that's because Chung only exists in the virtual reality game Second Life. Chung, or rather, her real-life counterpart, Ailin Graef, has gained attention -- and a BusinessWeek cover -- as the first person to reportedly become a real-world millionaire from her virtual-world business.How'd she do it? By buying, developing and selling virtual real estate. While much of her wealth is still tied up in Second Life's currency, Linden dollars, those can be sold for genuine U.S. dollars. Graef reportedly makes upward of $150,000 annually.Second Life is one of several massively multiplayer online role-playing games that are, literally, their own worlds. Julian Dibbell, author of "Play Money: Or How I Quit My Day Job and Made Millions Trading Virtual Loot," estimates the market for virtual items across games such as Second Life and Ultima Online has hit the $1 billion mark. "I think it's safe to say that it's at least $1 billion now," he says.Such numbers -- along with success stories like Graef's -- show there's real scratch to be made from online dirt. But just how much depends on a number of factors, of which only a handful are under your control. Here's how the virtual real estate game is played.