Grassroots Mapping (grassrootsmapping.org) is a participatory mapping project involving communities in cartographic dispute. This January, we worked with a series of organizations and communities to produce maps with children and adults from several communities in Lima, Peru. Seeking to invert the traditional power structure of cartography, participants used helium balloons and kites to loft their own �community satellites� made with inexpensive digicams. The resulting images, owned by the residents, are georeferenced and stitched into maps which are 100x higher resolution that those offered by Google, at extremely low cost. In some cases these maps may be used to support residents� claims to land title. By creating open-source tools to include everyday people in exploring and defining their own geography, Warren hopes to enable a diverse set of alternative agendas and practices, and to emphasize the fundamentally narrative and subjective aspects of mapping over its use as a medium of control.