Speech-recognition technology has come a long way since its first introduction 50 years ago. To win market acceptance, today's voice portals that enable voice control of voice-mail, e-mail, dialing, and Web browsing must take into account the end user's desired experience. A conversational VUI that follows person-to-person communication guidelines is the most critical element of a voice portal. Successful systems will allow users to interact with it in a natural and intuitive way that mimics the flow of ordinary conversation.