The following video demonstrate how the INRIA team try to use 3D cursors to enhance user navigation in a virtual world.
If your browser is not able to display the video, you can download it: here
You can read more about this work in this other W3D article.
In this PDF (EN) called “Design and evaluation of 3D cursors and motion parallax for the exploration of desktop virtual environments”, you will discover a part of INRIA work on the W3D Project.
You can view or download this PDF : here
As an illustration, you can watch this short video.