Max Payne, an alcoholic and drug-addicted virtual character, could inject much-needed new life in May after such a weak April, and down sales for most of this year.

FORBES: Connect

Girls sign up, they start out with a nude virtual character and they compete against other girls to earn so-called "bimbo dollars" so they can buy these virtually sexy outfits and go out clubbing.

NPR: Auctioning a Nude Pic of France's First Lady

As for trading virtual attributes, character possessions in the multiplayer game Everquest (such as a sword that an advanced player had won in a difficult level of the game) already trade on Ebay.

FORBES: Magazine Article

Second Life, as its name implies, is a virtual world in which members create an avatar and then use that character to live out a separate existence.

BBC: NEWS | Technology | Second Life 'child abuse' claim