In this excellent post, Peter Levine, who's a partner at Andreessen Horowitz, talks about the profound impact a CEO has on the culture of a company.
This is so true ... companies are defined by their cultures ... and cultures are defined from the CEO on down. You cannot manufacture a culture that is inconsistent from the beliefs and actions of a CEO. No matter how hard you try.
It is a must read for any aspiring CEOs. Remember that the expectations you have of others must be aligned with the expectations you place on yourself. And that the behaviour of your team will eventually be aligned with, and influenced by, your behaviours.