Research In Motion (RIM) is continuing to confront the encroachment of Apple's iPhone into its traditional business arena, with a second iPhone killer device, this time featuring a touch screen.

Reports of a touch screen phone, codenamed Thunder, first surfaced back in May this year. However RIM has launched the touch screen model on Wednesday, and it is called the BlackBerry Storm.

The device will be officially available sometime in the Autumn, exclusively to Vodafone subscribers in Europe, India, Australia and New Zealand, and Verizon Wireless subscribers in the United States.

A Vodafone spokesman told Techworld that the device would be available sometime in November.

RIM is making a point that its touch interface "enables easy and precise typing", following criticism of the difficulty of typing with the iPhone's on-screen keyboard. Unlike the iPhone however, the Storm has a "clickable" touch-screen, which apparently responds much more like a physical keyboard.

"The BlackBerry Storm is a revolutionary touch-screen smartphone that meets both the communications and multimedia needs of customers and solves the longstanding problem associated with typing on traditional touch-screens," said Mike Lazaridis, president and co-chief executive officer at RIM in a statement.

"Consumers and business customers alike will appreciate this unique combination of a large and vibrant screen with a truly tactile touch interface."

Essentially, the Storm's touch screen actually depresses ever so slightly when pressed. The user apparently feels a gentle click when the screen is released, similar to a key on a keyboard or a button on a mouse. RIM is hoping that this clickable touch screen will give the user a positive confirmation that they have made a selection, and should provide a more 'intuitive typing experience'.

The BlackBerry Storm offers the familiar navigation keys ('phone', 'menu' and 'escape') that are common to other BlackBerry smartphones, but adds support for multi-touches, taps, slides and other touch screen gestures, so users can highlight, scroll, pan and zoom for smooth navigation.

Like the iPhone, the BlackBerry Storm also features a built-in accelerometer, allowing its touch-screen to automatically switch between landscape mode and portrait mode as the user rotates the handset.

A SureType keyboard layout is available in portrait mode and a full QWERTY keyboard layout is available in landscape mode.

RIM has been diversifying from the traditional BlackBerry form factor of late to widen its prospective customer pool beyond business users. Last month, the Canadian handset maker introduced a "flip" or clamshell model, the BlackBerry Pearl Flip 8220. Then in August, it finally released the hotly anticipated BlackBerry Bold 9000, a better looking take on the traditional BlackBerry handset.

"It is clear that RIM is trying to make its device more attractive to consumers, as well as enterprises," said Tim Renowden, research analyst at Ovum. "With the Bold and Storm, RIM is continuing its drive into the consumer space, as well as shoring up its lead in the enterprise space."

"It will be interesting to see how well the touch-screen works in practise," he added. Renowden pointed to RIM's partnership deals with Facebook, MySpace, and other consumer-focused applications such as instant messaging, as evidence that RIM is seeking to broaden its appeal to consumers.

"There is a rising amount of touch screen competition to the iPhone, what with HTC's forthcoming Android handset, Nokia's 5800 Xpress Music, and now the Storm," he said. "It will be interesting to see how well the Storm's touch screen and user interface works. Users now expect a certain level of usability, the bar has been raised (by the iPhone)."

As would be expected, the Storm is a 3G device, and users can surf the web by EV-DO Rev. A or HSPA (High Speed Packet Access), but there is no Wi-Fi.

It does contain the usual BlackBerry emailing software, as well as a media player, built-in sat nav and mapping software, and a 3.2 megapixel camera.

It also has 1GB of onboard memory and up to 16GB of storage via microSD card, and the 3.26 inch screen (480 by 360 pixels) is apparently good enough to watch movies. The device itself measures 112.5 millimetres, by 62.2mm, by 13.95mm and weights 155 grams.

There are no details yet on UK pricing of the device, although Renowden feels that it will be 'aggressive'.