Presents a short biography of the winner of the American Psychological Association's Award for Distinguished Early Career Contributions to Psychology in the Public Interest. The 2012 winner is Marguerita Lightfoot for her leadership, innovation, and commitment to applying psychological principles to develop behavioral health interventions for vulnerable populations, particularly homeless adolescents and racial/ethnic groups. Lightfoot's professional career has been dedicated to addressing the HIV/AIDS epidemic both in the United States and Africa. She pioneered the use of computer-based interventions based on rigorous psychological principles, including the innovation of using text messaging and web-based social networking forums to deliver prevention messages to youth. She is dedicated to mentoring students and new researchers as well as working hand in hand with the communities she serves in order to effect change. Lightfoot's Award citation and a selected bibliography are also presented here.