American Association of Sexuality Educators, Counselors, and Therapists
http://www.aasect.org

Society for Scientific Study of Sexuality
http://www.sexscience.org

National Association of Social Workers
http://www.naswdc.org

American Psychiatric Association
http://www.psych.org

American Medical Association
http://www.ama-assn.org/ama

The ManKind Project
http://mankindproject.org