We have previously shown a new method of merging a direct view of the patient with an ultrasound image displayed in situ within the patient, using a half-silvered mirror. We call this method Real Time Tomographic Reflection (RTTR). This paper reviews our progress to date in developing an embodiment of RTTR that we call the sonic flashlight™. The clinical utility of the sonic flashlight for guiding invasive procedures will depend on a number of factors, and we have explored these factors through a series of prototypes. Responding to feedback from our clinical collaborators, we have upgraded various elements of our original apparatus and implemented a new generation of the system that is smaller, lighter, and more easily manipulated. We have improved performance as we gain a better understanding of the optical parameters of the system. Our results demonstrate in situ visualization of vasculature of the neck in a human volunteer and the anatomy of the eye in a cadaver.