This informal lunch talk will provide an introduction to the techniques and varied applications of adaptive optics. After a brief review of the technical fundamentals of natural and laser guide star adaptive optics, I will discuss a number of astronomical applications: differential astrometry, planet detection, transient survey follow-up, and optical interferometry. These applications have analogues in other areas, which I will describe. Progress in adaptive optics has always been intimately tied to the availability of highly specialized components: high speed cameras, deformable mirrors, lasers, and low-latency electronics. Throughout the talk I will touch upon the state of the art and indicate the types of adaptive optics systems that are being enabled through current development efforts.