The Nano Touch device currently being demoed by Microsoft research adds a wonderful twist to modern touchscreen tech: the back surface of the device is touch-sensitive too. Though this sounds clumsy at first, it's actually a rather neat solution to the problems of touch-control screens being obscured by the user's finger when in action--particularly if you're someone with larger fingers, or the device is particularly small.
Touch technology has been around in certain applications for decades, but it's only with the rise of portable electronic gadgets that it's really taken off. Touchscreen tablet computers have been out for a while, but remaine a rarely-used innovation--the rise of the netbook, and next-gen versions with touchscreens may change all that. And recently, spurred by the iPhone's elegant design nearly every significant cellphone maker has put a full-screen touch interface on a smartphone.
Nowadays multitouch technology is beginning to take over from older, simpler touch-response systems, pioneered most successfully by the iPhone and the multi-finger gestures that the trackpads on MacBooks now support.
Multitouch works because gestures combined with simple touch-navigation create a very powerful and "natural feeling" interface to gadgets--you can achieve complicated levels of interaction with a simple movement that would take either many keyboard clicks or much mousing using conventional input tech. And this line of innovation can only get more sophisticated as researchers invent new ways to include more powerful gesture-control into gadgets. But currently most touchpads are simple two-dimensional panel interfaces.
And that's why in the future perhaps the idea of a "touchpad" or "touchscreen" may disappear entirely: our gadgets will have "all-over" touch-sensitive surfaces, in complex 3D shapes and not limited to a specific "touch control" area.
This is not just a design idea gone mad: having a specific area for touch-control of a device is a limitation in current devices due simply to technology levels. An all-over touch-response, highlighted perhaps by the form-factor of the device, or delineated with particular markings on the gadget's shell, makes more sense for many devices.
A recent Apple patent seems to be pointing directly at this kind of touch interface, though in an adaptive sense. The application details how "portable multi-touch skins that can be wrapped around three-dimensional objects such as an iPod or steering wheel to provide additional GUI interfaces for those objects." The idea that your steering wheel could be configured to accept gestural control for your in-car systems is a compelling one, since it means more hands-on-wheel time and less distraction than reaching for a nearby control button.
Similarly you can imagine reaching into a pocket and tapping your MP3 player anywhere to get it to skip to the next track, or sliding your finger along your Bluetooth headphone to change the volume.
The possibilities for more powerful and more intuitive interactions with gadgets are endless with all-over touchpads. Of course the technology has to mature to the point that accidental inputs aren't easily achieved, or aren't disastrous if they do occur. As Douglas Adams noted, this is a pitfall for gestural-input devices: "as the technology became more sophisticated the controls were made touch-sensitive — you merely had to brush the panels with your fingers; now all you had to do was wave your hand in the general direction of the components and hope."