The investigators seek to shift current clinical practice in the treatment of social phobia so that more people with the disorder receive exposure therapy. The investigators will improve access to evidence-based treatment for social phobia with delivery of exposure via a computer - a modality that capitalizes on the fact that people with severe social phobia spend extensive hours on the computer; exposure therapy can come to people with social phobia "where they are." The investigators also will be the first to test the delivery of exposure therapy on an iPad. The study design improves the approach of existing research on computer-delivered programs for social phobia by testing how treatment affects real behavior - existing research has relied exclusively on self-report measures and assessment of diagnostic status. No studies have assessed actual behavior - either in the lab or in the real-world. This study will improve scientific knowledge by answering the question of whether or not DCS augments self-guided exposure therapy. The combination of a self-help program with DCS addresses many of the obstacles to treatment with therapist-guided exposure therapy. For example, there are not enough mental health providers trained in exposure therapy. Furthermore, social anxiety disorder is characterized by the fear and avoidance of social situations, and psychotherapy is inherently a social encounter. The effective combination of DCS and self-guided virtual reality exposure is an avenue for treatment to any sufferer with access to a computer and a prescribing physician. When the proposed aims are achieved, an innovative treatment will exist that did not before - self-guided VRE delivered via computer.