This paper describes my current project "Peripato Telematikos", an experiment in social cartography and public authoring, drawing influences from performance studies and art. The project relies on public participation to 'map' a locale or neighbourhood. The mapping process requires participants to undertake guided walks and use a mobile phone to send images of interest during the walk. As the images appear on the web site in close to real time, there is a performative aspect to the work. The images are sent to a custom hardware and software system, composing a gsm/gprs modem, sms/mms gateway software, php scripts and a mysql database. All entries are stored in the database and await approval. Once approved the images are immediately available for viewing and manipulation through an applet at the website http://www.peripato.net. The applet implements an experimental interface developed by the Human-Computer Interaction Lab (HCIL) at the University of Maryland that allows 'zooming' of all content. This allows the content to be manipulated by visitors to the site, allowing for an emergent montage of media elements.