Facebook creates a dual stock structure, but denies that it 'signals' an IPO

Facebook has taken a key step toward selling itself to public investors. Although the world's largest social network insists that the move doesn't mean the company is planning to go public, it's clearly designed to allow the current owners to maintain control of Facebook if it does go for an initial public offering.

Founded in 2004 in a Harvard dorm room, Facebook has been valued as high as $20 billion during the go-go years of the Web 2.0 bubble. Since the financial meltdown and recession, that valuation has dropped below $5 billion and hasn't been able to break $10 billion.