The New York City Department of Finance (DOF) partnered with the Center for Urban Research (CUR) at the Graduate Center of the City University of New York (CUNY) to evaluate the effectiveness of handheld devices enhanced with geographic information system (GIS) maps to improve the efficiency and accuracy of data collection for property valuation and tax assessment purposes. This report describes actual project implementation compared with initial objectives and expected outcomes, offers lessons learned and summarizes feedback from the DOF assessment team that field tested the devices and software application. Our general assessment about the feasibility of using hand-held devices for field assessment work is that the relevant technologies available are advancing rapidly, but the effort to deploy them is still highly complex. Any plan to implement these solutions should provide for considerable contingency time and the project be structured with great flexibility so as to accommodate uncertainties. Although this project did not establish the certainty of increased efficiency and improved data quality, the results strongly suggest that can be the case. We conclude from this study that the technologies are effective, and that the key elements to a successful implementation are strong management support and focused attention on the cultural shifts required of organizations undertaking the adoption of hand-held devices.