ABSTRACT: In recent years the ability to collect spatial information from volunteers has greatly expanded through the combination of Google Earth, geo-tagged photos and the Internet. A Geo-Wiki has been created to aid in both the validation of existing spatial information and the collection of new information through the powerful resource of crowdsourcing. A case study of a land cover validation Geo-Wiki is described, in which the tool is used to validate existing global land cover products. The potential of such a tool for other applications is also recognized.