Wearable computers provide constant access to computing and communications resources. In this paper we describe how the computing power of wearables can enhance computer-mediated communications, with a focus upon collaborative working. In particular we describe the idea of contextual communication, where contextual cues collected by the wearable computer are used to establish and enhance communication links. We describe the hardware and software technology we have developed to support contextual communication and two experimental contextual communication systems. The first, a wearable conferencing tool uses the user's physical location to select the on line conference which they connect to. The second, MetaPark, is a mixed reality educational experiment which explores communications, data retrieval and recording, and navigation techniques within and across real and virtual environments.