MOPET is a PocketPC-based application that uses a GPS device to monitor a user's position and speed on outdoor fitness trails. In addition to map-based and audio navigation assistance, it also offers context-aware exercise demonstrations using an X3D Humanoid-Animation virtual trainer. When the user approaches a fitness trail station, the GPS identifies the station, and a humanoid demonstrates how to correctly perform the exercise. The application renders 3D on PocketPC using OpenGL ES 1.1 (Hybrid's Rasteroid) and for Intel 2700G-based devices (e.g. Dell Axim X50V) using OpenGL ES 1.0.