On-line social networks provide a means for rapid communication between widely dispersed networks of people. The information generated by users of these networks provides an unfiltered snapshot of social mores and opinions at any point in time and is a hugely significant resource for those interested in human behaviour. Amongst social networking media the micro-blogging tool twitter is particularly noteworthy for functioning in near real-time and providing information on the spatial location of individuals at the point of posting. It thus becomes possible to reconstruct both social and spatial patterns of behaviours from an archive of users’ postings. In this paper we describe the development of a tool to harvest the geolocated tweets from users throughout the UK and the preliminary findings from analysis of some 1.87 million unique tweets collected over a 49 day period.