We have developed a new device for guiding invasive procedures with ultrasound (US), which we call the Sonic Flashlight (SF). We attach a half-silvered mirror and a small flat-panel monitor directly to an ultrasound transducer to project a virtual image of the US scan into its actual location within the patient. This permits the operator to guide a needle through the skin by aiming directly at the image, using natural hand-eye coordination rather than looking away from the patient at a conventional display. We believe the SF will increase accuracy, safety, and speed for a wide variety of invasive procedures and yield a faster learning of these procedures than conventional US displays.