This talk consists of two parts. In the first part, I will review how almost all the extra-solar planets discovered so far have been relatively nearby --- within ~500 parsecs from the Sun, and within about 2 AU from their parent stars. I will discuss how microlensing provides insights into the frequency of planets across the Milky Way, and up to several AU from the host stars. In the second part, I will discuss the technique of astrometric microlensing, and two HST programs underway aimed at the first detections of isolated, stellar-mass black holes through this technique.
