The touch screen interface is one that has been a long time developing. The first touch interfaces used in computers were Wacom graphics tablets, which were developed by a Japanese company to support writing Japanese ideograms as a text input method. Wacom's means to measure both the pressure area and direction of a touching pen or stylus has led to the innovative handsets and touchscreens we have today.

As a smart phone interface, touch screens started out with the original Apple Newton, but unfortunately it didn't take off - the form factor was too large to be convenient, and battery technology made them heavy. It was greatly improved by the Palm Pilot, which enjoyed immense popularity in the late 1990s, becoming more powerful but requiring less battery power to operate. Their modern day descendant the Palm Treo has since foregone the touch screen in favour of a thumb-driven keyboard.

Touch screen phones started taking off again in the first half of 2006 - nearly a year and a half before the iPhone made it "the must have" feature on any mobile phone. The phones got some dedicated followers, but the overall prospect of using the touch screen for carrying out any significant data work was daunting and frustrating - mostly because the software wasn't up to it, and the menus weren't built around the user experience.

With the iPhone, we saw the first example of someone creating a touch interface right - the touch screen on an iPhone or iPod touch is amazingly sensitive to both multiple points of contact and to noting the direction of travel. It's this software/hardware integration that makes the iPhone such an elegant piece of equipment, with the ability to pinch to zoom out, stretch to zoom in, and a fingertip flick to roll through your contacts or playlist.

New Smartphones, new touch technology

With the popularity of the iPhone, it's no surprise that other mobile phone companies are going to be hitting the market soon with their own touch screen models. Samsung, for example, is releasing the Tocco which is smaller and thinner than Apple's model. It has a touchscreen and allows for the dropping and dragging of widgets for the user's convenience.

Still at the forefront of mobile phone sales, Nokia isn't going to be left out of the smartphone race. They are currently working on a touchscreen model prototype currently referred to as Tube. With built-in GPS and a nice widescreen display, the phone will fit in nicely with the competition. It's also believed to support handwriting recognition.

Clearly, Apple has led the touchscreen revolution and it promises to be a great year in smartphones both for consumers and for the industry.

What's next? Well, probably two things taken from gaming consoles - sensitivity to direction of motion for the unit as a whole (think of the Nintendo Wii), and something called haptics. Haptics is all about the study of touch. Integrating haptic technology within a touch screen could enable phones and other devices to allow us to experience a whole new set of senses.