Laserscanners are state of the art for acquiring geometrical information of the environment. But for several applications low cost is mandatory while high accuracy is not necessary. For these cases an alternative low-cost sensor-system is presented. Its total cost is about 100 US Dollar. The paper describes characteristics of the Sharp Triangulation Sensor GP2D12 based on theory and experimental results. Furthermore, the concept for its use as a scanner is shown and experimental results are presented. The scanner's range is 180 deg and 80 cm in width. It scans in steps of 2 deg with range resolution of 5% to 15% depending on the distance. An application example for indoor mobile robots is given.