Relentless reform and increased accountability in education in England have led to increasing attention on the effectiveness of teachers' professional development (PD). A shift away from top-down approaches to PD has led to more emphasis placed on in-house, collaborative models. This paper reports on qualitative research conducted in the south of England, which explored the notion of postgraduate certificate in education (PGCE) student teachers on school placements as legitimate peripheral participants in communities of practice. It focuses on the benefits to the "old-timer" of training a "newcomer" rather than the original approach of examining how the community shapes the apprentice. It was found that school stake holders recognized the positive contribution made to teachers' PD by the student teachers. This paper suggests that schools should be encouraged to build upon communities of practice to realize the benefits to themselves of engaging in training student teachers.