Theodore Roosevelt crafted a masterpiece of service. He served people in every aspect of his life. His legacy was transformational, encompassing his family, his nation and the world.

Ronald Reagan was unusual in being an authentic personality. Unlike many professional actors - and politicians - he was much the same behind the curtain as in front.

Effective leaders at a high level tend to be skilled actors. Franklin Roosevelt is said to have to quipped, on being introduced to Orson Welles, that they were the two greatest actors in America. The story may be apocryphal, but the message rings true.

President-elect John F.Kennedy said to Robert McNamara that there's no school for presidents, or, for that matter, for secretaries of defense.

Ronald Reagan memorably combined intimacy with distance.

If leadership is, fundamentally, about serving others, then any one person should be able to move between being a "leader" and a "follower."

Wal-Mart, with its legendary focus on customer value in terms of price, is innovating in sustainability. Now, we're beginning to see the mirror image, a convergence, as the not-for-profit sector is beginning to serve more effectively by applying private sector accountability and efficiencies to social needs. This reflects a rising recognition that to serve others best requires more than good intentions; it mandates a focus on real-world results. Bill Gates and Warren Buffett are among the most conspicuous advocates and representatives of this transformation.