We hope the site will be a place where Californians can see how various aspects of their communities affect their health. The information displayed will be a catalyst for online conversation and action, and hopefully infuse the public discourse on health care reform with new voices advocating for both equity and access. Based on feedback from partners, The Opportunity Agenda will map a number of state-wide health issues, integrating data at the smallest feasible geographic level (e.g., Census tract or zip code level). For example, these maps could display the location of key community-level health resources, such as the presence of community health centers and hospitals, the availability of language assistance services, as well as health risks, such as concentrated poverty, sources of environmental degradation, industrial waste sites, etc. We will also present a demographic data overlay on the map, to show how the distribution of health risks and resources across communities contribute to health disparities. The demographic data will be periodically updated and changed using a geoserver, so that the map will change as neighborhoods do. User-generated content—stories, ideas, and activism contributed by everyday Californians—will also be a feature of these maps, which will allow users to understand how to use the site and enter their own content. To support partners’ advocacy, we will incorporate a letter-writing capacity and a networking function in the form of either a blog, forum, or organic groups. The site has the potential to be a platform for members of all communities to become citizen journalists, community researchers, or simply more informed about the health resources in their neighborhood.