Photoacoustic tomography (PAT), emerging approximately one decade ago, is a novel biomedical imaging modality based on the use of laser-generated ultrasound. PAT combines the high contrast and spectroscopic specificity of optical imaging with the high spatial resolution and large penetration depth (7-10 cm) of ultrasonography. With the capability to image important physiological parameters such as the total hemoglobin concentration, oxygen saturation, and even the metabolic rate of oxygen, it is highly complementary to conventional ultrasonography, and has opened up many new opportunities for novel clinical applications. Up to now, PAT has demonstrated a wide array of applications in both the clinic and basic biomedical research, in particular, for the diagnosis and therapy guidance of cancer, cardiovascular diseases, and abnormalities related to the microcirculation. In this article, we summarize the progress on some new PAT techniques developed by us during the past few years, including blind deconvolution, compressed sensing, and novel molecular imaging techniques. In addition, we briefly review the state of the art of the technology development of PAT, with particular emphases on its applications in breast cancer diagnosis, noninvasive sentinel lymph node mapping, and intravascular imaging.