while touchscreen devices are more ubiquitous than ever, really only allow users to draw in two
dimensions. beyond is a concept that allows users to sketch in three dimensions of an interactive surface
developed by jinha lee and hiroshi ishii of the MIT media lab. the system utilizes a collapsible input
device for direct 3d manipulation. the small pen-like tool collapses into the digital world when pressed
against the screen, giving the illusion that it is inside the virtual space. by moving the pen around the
screen and adjusting its height, users can draw objects in three dimensions. by adding an interactive
glove element, the system can even be used to draw cubes, cylinders and other three-dimensional objects.
while the concept is quite novel, it could become an indispensable tool for designers sketching digitally.

http://tangible.media.mit.edu/person.php?recid=81