Kilometer-Scale Neutrino Detectors: First Light

This is a brief report on the status of neutrino "astronomy" at a time when the kilometer-scale neutrino detector IceCube is approaching completion. We revisit the rationale for constructing gigantic neutrino detectors by transforming large volumes of natural ice and water into Cherenkov detectors. With time, the motivation for building such instruments has come into clear focus, and the requirement for their kilometer scale has been rationalized with improved accuracy. We will discuss the performance and some selected results of IceCube based on data taken during construction.