The self-organization of social networks and the emergence of ideas have both been studied extensively in recent years, but seldom in a single framework. In this paper, we describe a distributed multi-agent model for the self-organization of social networks from encounters between agents with specific ideas, which are seen as combinations of words. Each agent maintains a semantic network of the words it knows, which implicitly defines the ideas in its repertoire. Agents exchange their ideas over their social networks, and incorporate the received ideas in their semantic networks. Social bonds are made and broken based on the agents' social and semantic preferences (i.e., shared ideas), leading to the emergence of social communities. Thus, the model embodies a circular interaction between the formation of social networks and new ideas. We mine the resulting communities for novel ideas that are generated by their members, and look at the effect of interaction choices on their formation.