This paper presents a first prototype of an interactive 3D reconstruction system for modeling urban scenes. An Augmented Reality scout is a person who is equipped with an ultra-mobile PC, an attached USB camera and a GPS receiver. The scout is exploring the urban environment and delivers a sequence of 2D images. These images are annotated with according GPS data and used iteratively as input for a 3D reconstruction engine which generates the 3D models on-the-fly. This turns modeling into an interactive and collaborative task.