A lot of people think that what Apple is doing with capacitive touch screens and touch-based user interfaces is magical, but what if you could interact with a phone that was just a hologram? A team at Microsoft Research has put together a "Holodesk" which not only displays three dimensional holograms, but also lets you physically interact with them. It uses a Kinect sensor to see your hands or other physical objects within its view and models those objects in real time in order to calculate how they interact with the virtual holographic objects. Then there's another camera looking at your face to see where you're eyes are so that it can adjust the perspective of the 3D holographic objects' display in order to compensate for your angle of view. Check out the video below and around the 2:40 mark you'll see the user interacting with a holographic Windows Phone.
Of course, I can't imagine you would cary around a holographic phone in the future, but you can see that Microsoft is well on their way to bringing some science-fiction to the real world.