Portraits of Power

(Fortune Magazine) -- Power is highly mutable. Take the world's two richest men, a couple of bridge-playing buddies named Bill and Warren.

They've been immensely wealthy for years, sure. But now, by combining their fortunes in a single philanthropic organization, they, along with Bill's wife, Melinda, just might wipe out deadly infectious diseases.

Or consider Al Gore. You'd think that after being a heartbeat - or one Supreme Court vote - away from the presidency, putting together a slide show on global climate change wouldn't feel much like a return to center stage. Think again.

In part because of the ever-shifting value of influence in the business world, this year we decided to eliminate rankings from our annual study of the subject and instead provide, literally, snapshots of power: In the gallery that follows are 25 portraits, photographed by Albert Watson, of the characters who had the most impact on 2006.

Often, of course, power comes with the keys to the office. Such is the case with Fed chair Ben Bernanke, who, like his famous predecessor, moves markets with the simplest utterances.

Or with ADM's new CEO, Patricia Woertz, who is suddenly the most important person in the newly important world of ethanol.

Others have made their own power plays. Who ever thought it was possible for one man to dominate the steel industry a century after Andrew Carnegie did? Lakshmi Mittal, that's who.

Away from the camera, we subjected two of our powerful subjects to deeper scrutiny. Managing editor Andy Serwer and Washington bureau chief Nina Easton asked Treasury Secretary Hank Paulson about his plans for the U.S. economy.

And senior writer Roger Parloff profiled Larry Sonsini, the Silicon Valley lawyer who has spent decades accruing power and who, this year, endured the inevitable scrutiny that accompanies it.

A Picture Portfolio by Albert Watson contributed to this article.