The paper studies how multi-camera systems can be used for registering trajectories. A sensorized tool (a paintbrush)has been used to track the movements of a painter. Its position and its orientation is recorded using a rigid body registration technique on the reflective spheres, which generates its trajectory.Additional treatments for smoothing the acquired trajectory enable a robot to reproduce its movement. Such technique for the registration of tool movements relieves the robot programmer of a fastidious trajectory planning and remarkably quickens the programming phase