If you look around, you'll find plenty of formal and informal opportunities to mentor someone. Chances are, your professional membership society has a formal mentoring program. Or, you can find an opportunity through MENTOR: The National Mentoring Partnership (MENTOR).
Many academic programs also offer mentoring programs. For example, I'm a mentor through the University of Maryland University College Biotechnology Professional Mentoring System. I've also participated as a mentor through programs offered by the Alliance for Continuing Education in the Health Professions.
The American College of Physician Executives offers a CME course titled, "Coaching & Mentoring Physicians to Higher Performance." And, the American College of Healthcare Executives has a Leadership Mentoring Network Manual that you can get online (PDF).
Consider the benefits associated with giving back and join a mentoring program this fall. You'll meet some interesting people and you'll be helping someone else in a meaningful way.