This article describes an environment based on the user's physical location to tell interactive stories on mobile devices. First, the technology to physically locate the user is presented. Thence the project, called MPISTE, is put into context with related projects. The paper continues with the description of the project and its design as part of a project to develop an affective virtual guide. The work described herein consists of two parts. The first one is the client, which was developed (using J2ME) for Smart-phones. The client is connected via bluetooth to devices such as RFID and GPS for locating the user. The second one is the server (webserver), which receives requests from the former and these are answered via servlets, which relay petitions to a relational database. The communication protocol used to communicate the mobile phone with the server is EDGE/3GSM.Finally, an ongoing application is presented: museum guidance for the severely motor-impaired. MPISTE is mounted on a robotic wheelchair which guides the user among the museum's rooms while providing location-aware interactive audio stories.