Simon Sinek has a simple but powerful model for inspirational leadership all starting with a golden circle and the question "Why?" His examples include Apple, Martin Luther King, and the Wright brothers -- and as a counterpoint Tivo, which (until a recent court victory that tripled its stock price) appeared to be struggling.
This seems to be of important use, but haven't worked on any project that would require this solution. However, it doesn't harm to have this in resources.