Post-Traumatic Stress Disorder (PTSD) is a condition in which a person responds to a traumatic event, such as war, a car accident, or physical abuse, with prolonged feelings of fear, helplessness, or horror. This disorder can have a significant detrimental impact on the lives of those affected by PTSD as well as their friends and family. In this paper, we outline the potential for computing technologies to assist with all aspects of the experience of Post-Traumatic Stress Disorder, including recognizing the pre-trauma disposition for PTSD, identifying the symptoms, helping with diagnosis, and aiding in the treatment and assessment of treatment. The content of this paper is based upon an extensive review of the literature and our consultations with domain experts and therapists who treat PTSD. We outline a number of opportunities for computing technologies to play a role in improving the lives of those with PTSD as well as challenges for working in this space. We also describe specific design considerations for computing technology designers.