Tunnels are 3D graphical sliders which modify the appearance of, or "modulate", one or several 3D objects simultaneously using these objects as cursors themselves. They rely on a strong visual feedback to provide multiple scales and parameters combinations which makes them appropriate for the use in immersive virtual musical instruments. In this paper we present applications of the Tunnels for collaborative modulation tasks, for avatars and weapons modifications in 3D video games, and for the control of interactive scenarios. We also propose several improvements to the Tunnels such as a method for storing them and a two-dimensional version called Grids.