Precision tests of the gravitational inverse-square law have covered inter-mass separations from centimeter scales out to about one light-year, but until recently we had almost no information about gravity at shorter distances. New experiments using methods from classical gravitation, low temperature physics, and surface science are now seeking new fundamental forces that might exist over the whole ÔmesoscopicÕ range, from centimeters to nanometers. Attention is focused especially on millimeter scales, both because this is the current frontier for detecting forces of gravitational strength, and because several theories make testable predictions at these scales. In this talk I will review our knowledge of gravity at short distances, survey current experiments, summarize recent results (including those from our laboratory), and speculate on the future of this experimental frontier.