Avatars in networked 3D virtual environments allow users to interact over the Internet and to get some feeling of virtual telepresence. However, avatar control may be tedious. Motion capture systems based on 3D sensors have recently reached the consumer market, but webcams and camera-phones are more widespread and cheaper. The proposed demonstration aims at animating a user's avatar from real time 3D motion capture by monoscopic computer vision, thus allowing virtual telepresence to anyone using a personal computer with a webcam or a camera-phone. This kind of immersion allows new gesture-based communication channels to be opened in a virtual inhabited 3D space.