Who: Timothy Geithner, Secretary of the Treasury

How he fiercely influenced finance: The Treasury chief briefs Obama on the economy every day the president is in town and spends more time in the White House than most previous treasury secretaries, notes the  McClatchy-Tribune News Service.

Formerly the president of the Federal Reserve Bank of New York, Timothy Geithner is now one of the youngest Treasury secretaries ever appointed.

As Treasury Secretary, Geithner directs the government's spending on the financial crisis of 2007-2010, including the allocation of $350 billion of TARP funds.

No. 28 on Forbes' list of the world's most powerful people, Geithner is recognized for helping to revive the banking industry, cutting projected losses from the $700 billion bailout fund to about $50 billion, and overseeing the biggest overhaul of financial regulations since the Great Depression.

Treasury&Risk named him one of this year's 100 Most Influential People in Finance for standing his ground amid "criticism and abuse from 100 senators and 435 Congressmen, as well as countless experts."

The Treasury Secretary was also recognized as one of the year's most influential people in corporate governance by the National Association of Corporate Directors. As such, Geithner is "shaping the future of corporate governance at a time when American business looks to restore investor confidence and restore economic growth," said NACD CEO and President Ken Daly in a statement.

What's next: Under the financial overhaul bill, Geithner is responsible for setting up the much-anticipated Consumer Financial Protection Bureau, as well as leading a new council of financial regulators who will oversee the economy for signs of risk.

"His quiet determination will be further tested as he tries to sell Europe on the U.S. vision for financial reform and regulation," notes Treasury&Risk. 

He has also urged lawmakers earlier this month to resolve the issue of expiring tax breaks by the end of the year, according to the Washington Post. "It would not be a responsible act of government to leave this level of uncertainty hanging until next year," he noted.