Here are some video clips which demonstrate the capabilities and possibilities you can achieved with a multi touch screen display, currently one of the most active research pursued by computer scientists involved in haptic interface research.
This one is created by Jefferson Han, who apparently drop out from his senior year in Cornell University to join a startup company. He's now a research scientist in NYU. This piece of technology is based upon frustrated total internal reflection, an optical phenomena he took advantage of.
here's another version, with a transparent screen. It's called Touchlight. This one is created by Andy Wilson, who's part of Microsoft Research. He got BA in CS from Cornell University, and his PhD from MIT Media Labs.
Here's another one which Wilson made. It's called PlayAnywhere.
I'd have to say Jeff's gives faster response time, which is very crucial in creating an input device. Wilson's touchlight is good and novel because it uses a transparent screen, but as we can see from the demo, there's not much applications which exploit such features. Jeff's gives lots of demos and really open up the many possibilities of taking advantage of this novel and new form of human computer interaction.
One thing I should insist that, all these technologies have existed for some time, but due to many factors including market acceptance and technology maturity, they're often delayed years and even decades.
So my point is, at this point of time, many futuristic technologies are already available, waiting to be crafted into novel applications, or to be perfected.
Allow me to digress. In the 60s, we possess the theoretical technology to allow us to travel up to nearly 0.1c. This is very impressive, considering the difference from the speed of light is just a single order of magnitude. Nevertheless, that technology made use of nuclear warheads, and that means possible pollution and hazardous radiation to lives on earth as the rocket makes its way to the space. The technology has since been abandoned, and we still rely on chemical energy, an energy form we've been using since we started off as boiling proteins and nucleic acids in some random unknown warm pool during primordial times. Now that it's 21st century, I expect we should've reached the point of making good use of nuclear energy and of course, finding novel and safe ways to dispose off the radioactive fuel rods. But alas, our progression to type I civilization is halted. Despite the potential danger to environment, I still believe it's up to technological advancement and a leap of faith to make that transition into an advanced yet peaceful and safe civilization.