Most current work on gesture recognition focuses on the analysis of complex video sequences. In this paper we present an alternative approach that is intended for simple gesture control using a relatively inexpensive pyroelectric array detector. The detector is manufactured using standard wafer processing techniques. It consists of a 16 element passive infrared sensor array that responds to changing infrared signals, such as are generated by a hand moving at a distance of some tens of centimetres in front of the array. There is quite a large variation in the responsivity of the pixels within the array, but despite that it is relatively easy to use differential signals from the array or to apply a simplified version of an image processing algorithm to track movement in front of the detector. We have developed a prototype system that can recognise hand movements in different directions in front of the detector. This has allowed us to develop a demonstrator system that can be used to control, for instance, a PowerPoint presentation by gesture.