The flow of spoken interaction between human interlocutors is a widely studied topic. Amongst other things, studies have shown that we use a number of facial gestures to improve this flow - for example to control the taking of turns. This type of gestures ought to be useful in systems where an animated talking head is used, be they systems for computer mediated human-human dialogue or spoken dialogue systems, where the computer itself uses speech to interact with users. In this article, we show that a small set of simple interaction control gestures and a simple model of interaction can be used to influence users' behaviour in an unobtrusive manner. The results imply that such a model may improve the flow of computer mediated interaction between humans under adverse circumstances, such as network latency, or to create more human-like spoken human-computer interaction.