The 25 Most Influential Executives Of 2012

23. Mark Zuckerberg

Chairman and CEO

Yes, Facebook's long-awaited IPO tanked. But the social networking behemoth is one of the biggest websites on the Internet, and Zuckerberg's company is changing the way we communicate in the 21st century. His name is synonymous with social media, and Facebook is expected to branch out beyond it, possibly into mobile computing or business class software.