In the traditional application model, services are tightly coupled with the processes they support. For example, whenever a server's process changes, existing clients that use that process must also be updated. However, electronic commerce is moving towards e- service based interactions, where corporate enterprises use e-services to interact with each other dynamically, and a service in one enterprise could spontaneously decide to engage a service fronted by another enterprise. In this paper, we clarify the relationship between currently developing standards such as the Universal Description Discovery and Integration (UDDI), the Web Services Description Language (WSDL), and the Web Services Conversation Language (WSCL), and propose a conversation controller mechanism that leverages such standards to direct services in their conversations. Using such a mechanism means that services can be written as pools of methods independent of the conversations they will participate in. Even the specific method names can be decided on independently of the conversations. The services can spontaneously discover each other and then engage in complicated interactions without the services themselves having to explicitly support conversational logic. The dynamism and flexibility enabled by this decoupling is the essential difference between applications offered over the web and e- services. 15 Pages