8x8 is a concept for a large (1m by 1m) interactive man/machine interface. Created by Jacob Remin, 8x8 is apparently still in early design stages. Remin has been exploring various sensor designs including using 2 theremin-like antennas to determine x/y position on the grid.
The 8x8 project is ongoing, and Remin is blogging his progress as he goes. Visit his site to learn more about 8x8.