MarketWeek: Social networks at crossroads: From mainstream to 'lame'stream?

A few years ago, social networking Web sites were just some newfangled technology that college students loved. But over time, they have metamorphosed into an unavoidable Internet phenomenon that is changing the way people of all ages keep in touch with friends, find long-lost acquaintances, explore new hobbies and even look for employment. And now Facebook is hoping to take its popularity and name recognition to the next level. But as social networks become more popular, especially among adults and potential employers, they may also lose some of their appeal.