A system for performing interactive virtual reality sessions without constraining the mobility of a user is disclosed. The system allows a user to remain fully mobile while participating in an interactive virtual reality session. The system comprises a handheld computing device having a display, user input controls, a location sensing device and a user sensing device. To conduct a virtual reality session, a software application is loaded from a memory. Then, the computing device determines its position within a space using the location sensing device, and the user sensing device establishes a relationship between the user's eyes and display. This relationship is used to provide the user with the same perspective as would be achieved if viewing the simulated session in real life. User input controls allow the user to control aspects of the session to further enhance the user's experience.