In Seven Habits of Highly Effective People, Steven Covey describes the concept of circles of control, influence, and concern. Succinctly, this concept states that you should only focus on the few things you can control and influence, and not on the many for which you are powerless.
This article describe an innovative retrospective process that one can use to help focus a Scrum team on the items they can control or influence.
This is a nice idea.