A well-developed literature base exists and continues to grow on the topic of teacher leadership; however, it remains largely an academic topic and even though inroads have been made, teacher leadership remains more a concept than an actuality. Teachers have always been leaders, but there is little evidence that a focused, collaborative movement exists in public schools designed to promote and support widespread teacher leadership in the profession. We know that sustained, effective school leadership strengthens student achievement especially when coupled with a supportive school climate that encourages collaboration and risk-taking; teachers and principals alike have reciprocal roles in building and sharing leadership. Unless and until the concept of teacher leadership is embraced and developed, "just a teacher" will remain the prevailing habit of mind in the nation's schools.