What is your idea of leadership?

In doing a bit of a brain dump on my leadership skills at work and outside of work I am having a difficult time defining leadership. How do you define leaderhip?

Is it teamwork, managing, taking initiatives? Is it all of that or something else? Wikipedia gives the definition of leadership as:
"the ability of an individual to influence, motivate, and enable others to contribute toward the effectiveness and success of the organizations of which they are members".

Leadership as it is narrowly defined seems pretty clear to me, but what is it that business schools look at someone and say, "YES. They are a leader" Particularly when our leadership experiences are more subtle.

I think of leadership as
-Taking initiatives and going beyond what is expected
-Managing people and projects and how you handle them in good and bad circumstances
-Having the ability to get people to follow your initiative and contribute
-One who inspires people to bring out the best in themselves to serve the greater group/organization.

I might be thinking too much here, people, but I'd love to hear what you guys think