Our understanding of the distribution of matter in the local universe has changed immensely in the past two decades. The rapid increase in the number of redshift measurements available for use in analyzing the structure of the universe continues unabated. HI redshifts have contributed significantly to our current knowledge, and will continue to play an important, albeit supporting, role in the future work in this area. The Sloan Digital Sky Survey will open up the exploration of the universe to unprecedented depths, and the new generation of large ground-based telescopes will likely push pencil-beam surveys to redshifts of 1 and beyond. These are truly exciting times in observational cosmology! Stay tuned.
Acknowledgments. JJS would like to express his gratitude to Riccardo Giovanelli, who taught him all that he knows about HI observations and most of what he knows about poker, and to MPH, who contributed many of the figures for the lecture presented in Minnesota and then stepped in to help push the writing of this review to completion. Thanks are also due Evan Skillman for the invitation to participate in the Minnesota Lecture Series, and to Evan, Don Garnett, Greg Aldering, Steve Odewahn and Chip Kobulnicky for their hospitality during his visit to Minneapolis. MPH receives support from NSF grants AST-9218038 and AST-9023450, and JJS acknowledges a grant from Research Corporation.