Human natural face-to-face communication is characterized by inter-personal coordination. In this paper, phenomena are analyzed that yield coordination of behaviors, beliefs, and attitudes between interaction partners, which can be tied to a concept of establishing social resonance. It is discussed whether these mechanisms can and should be transferred to conversation with artificial interlocutors like ECAs or humanoid robots. It is argued that one major step in this direction is embodied coordination, mutual adaptations that are mediated by flexible modules for the top-down production and bottom-up perception of expressive conversational behavior that ground in and, crucially, coalesce in the same sensorimotor structures. Work on modeling this for ECAs with a focus on coverbal gestures is presented. (C) 2010 Elsevier B.V. All rights reserved.