Our immersive virtual reality devices are computer-based, and allow participants to view and manipulate graphical representations of physical reality. Stimulating the senses of sight, sound, touch, and smell simultaneously, our virtual reality devices envelop the participant in dynamic filmed or computer-generated imagery, and allow the participant to interact with what he or she sees using simple controls and body motions. Virtual reality products have traditionally employed head-mounted displays that combine high-resolution miniature image source monitors, wide field-of-view optics, and tracking sensors in a unit small and light enough to be worn on the head. These products usually surround the participant with dynamic three-dimensional imagery, allowing the user to change perspective on the artificial scenes by simply moving his or her head. Virtual reality devices have in the past been used primarily in connection with electronic games, as, by surrounding the player with the sights, sounds, and smells he or she would experience in the real world, play is made far more realistic than it would be if merely presented in a two-dimensional flat screen display. Now, however, virtual reality is finding increasing applications in the advertising/promotion and training/simulation markets.