A small local volunteer effort to improve timely measurement and reporting of convective precipitation in northern Colorado has grown, ten years later, into a national grassroots network of thousands of enthusiastic volunteers. Equipped with plastic rain gauges, snow measurement rulers, and foil-wrapped foam "hail pads," participants are collecting research-quality precipitation data. Leaders at the state and local level are using a variety of techniques to recruit, train and motivate new volunteers creating what will soon be the largest precipitation measurement network in the country. While automation of most meteorological measurements is now standard practice, CoCoRaHS continues to rely on manual measurements for all forms of precipitation. Thousands of individuals of all ages participate in data collection. The data are immediately processed and displayed on the CoCoRaHS website (http://www.cocorahs.org). This process yields continuous learning opportunities for participants and a rich new data set for a variety of meteorological and hydrological monitoring and research applications. Examples of how this low-tech community-based volunteer program is contributing to integrated climate monitoring, research, and education will be shown. Possibilities for greater volunteer participation, new collaborations, and applications will be described.