The Wii may be a nascent stepping stone into the future of HCI tools, but with the I/O Brush from the MIT Media Lab (a wooden paint brush that includes a camera and touch sensors), the world is your pallette. You can even "paint" with motion.
I/O Brush - (Don't miss the video down at the bottom)
Throw your digital pics around on a tabletop? Flick them from the table onto the wall? Watch them get sucked into a black hole sitting near your coffee mug? It's all possible with "Cruiser", a tabletop User interface, developed at the University of Sydney.
For an LCD touchscreen take on things, see Perceptive Pixel's Multitouch User Interface which gives us a peak into an utterly seamless multi-dimensional and collaborative world of touch.
If you can't get enough of the future of UI, take a virtual stroll through the HitLab where a slew of wild interface movies and demos await you...