Participatory search can be defined as a search service framework where each participant takes care of gathering information and contributing indexes to a central location where the indexes are integrated and deployed for running a search service. Participatory search has distinguishing characteristics with respect to other search service architectures, among these the ability to share with others material that is not available to traditional search engine crawlers. We present the architecture for participatory search and a protocol for index exchange that we are developing. A deployment niche for participatory search is the implementation of search services for community networks.