A pre-requisite for the Semantic Web to become a reality is the availability of metadata. Despite its maturity in many aspects, semantic technology faces a severe lack of semantic content: only few well-maintained domain ontologies can be found on the Web and the amount of annotated data is rather limited. We believe that this situation is caused by the pre-dominant ontology building paradigm: a small team of domain experts and knowledge engineers build and maintain ontologies. The actual user community is not involved in the process. In this paper, we propose a paradigm shift from the expert-centered to the community-grounded evolution of lightweight domain ontologies. Furthermore, we delineate the myOntology approach to building lightweight ontologies in a community-driven fashion based on the Wiki philosophy and the idea of combining human and computational ntelligence, we then describe the portal and provide a short walk-through. Next, we provide the valuation results and give preliminary evidence that MyOntology is a high-usability solution. Finally, we outline the next steps in the development of MyOntology as a solution for tapping the wisdom of crowds for building ontologies.