Comet-VR is an online management tool that provides a simple and reliable method for estimating soil carbon sequestration.  Presently, the tool is being used by producers, consultants, and scientists for making these estimates on crop and range land.  New research and development is improving and expanding Comet-VR’s capabilities.  This includes improvements in soil carbon change estimates by increasing the number of management and soil type options available to users; expanded options for estimating carbon changes resulting from agroforestry practices; and easier methods for users to give feedback on their experiences using the model. Comet-VR delivers an estimate of annual soil carbon fluxes along with fuel and fertilizer use.  This tool can aid a producer in making carbon-wise management decisions. Producers provide their historic, current and alternative farming and grazing practices into the user interface, which then provides estimates of changes in fuel use, fertilizer and carbon storage for each alternative scenario.Comet-VR utilizes the Century soil carbon model to provide estimated soil carbon changes resulting from changes to land management. Century is a generalized biogeochemical ecosystem model which simulates carbon (i.e., biomass), nitrogen and other nutrient dynamics. The model simulates cropland, grassland, forest and savanna ecosystems and land use changes between these different systems.  The Century Model was developed by Colorado State University (CSU) and the USDA Agricultural Research Service (ARS). Comet-VR was developed by CSU and the USDA-Natural Resources Conservation Service (NRCS) to aid agricultural producers in estimating soil carbon changes to be reported through the Department of Energy 1605(b) Voluntary Reporting of Greenhouse Gases Program.  In 2006, NRCS offered financial incentives to qualifying cooperators to utilize Comet-VR through their Conservation Security Program.  During this year, NRCS provided over $450,000 to 900 cooperators in 18 states to explore various soil carbon sequestration estimates associated with land management changes using Comet-VR.