Public participation geographic information systems (PPGIS) support collaborative decision-making in the public realm. PPGIS provide advanced communication, deliberation, and conflict resolution mecha nisms to engage diverse stakeholder groups. Many of the functional characteristics of Web 2.0 echo basic PPGIS functions including the authoring, linking, and sharing of volunteered geographic information. However, with the increasing popularity of geospatial applications on the Web comes a need to develop concepts for scalable, reliable, and easy-to-maintain tools. In this paper, we propose a cloud computing implementation of a scalable argumentation mapping tool. The tool also illustrates the opportunities of applying a Web 2.0 model to PPGIS. The searching, linking, authoring, tagging, extension, and signalling (SLATES) functions are associated with PPGIS functionality to produce a participatory GeoWeb tool for deliberative democracy.