Initially, today’s conceptualisations, technologies and visualisations of a modern “mapping of the city” will be presented. The conceptualisations include web-based mapping projects (e.g. Google Mashups), projects centring on resident participation and agitation with the help of location-based services and interventionist artwork. The (continual) mapping combined with aesthetic, interactive-dynamic visualisation and the provision of urban data (flows) represents an important basis for discussion and decision-making processes in the city.