Apple's iPhone isn't likely to take the business market by storm, but it will certainly rattle the mobile phone incumbents and make them rethink common user interface tenets.

With the Apple cult breathlessly following his every word, CEO Steve Jobs used the Macworld conference in San Francisco to reveal the long-anticipated launch, a sleek device that combines the functions of a mobile phone, iPod and web-browsing tool.

About the size of a pocket notepad, the iPhone is a quad-band, AT&T-Cingular GSM phone. It supports 802.11b/g Wi-Fi data links and AT&T-Cingular's Edge WAN data service (with speeds averaging 70K to 135Kbps). The battery is said to support five hours of talking, video or web browsing, or 16 hours of audio.

None of that is particularly remarkable. Other smartphones of roughly the same size boast these and other features of the iPhone, including music storage.

What sets the iPhone apart is its user interface, which is maddeningly elegant. Maddening because it is pathetic that so few other vendors pay as much attention to ease of use.

The heart of the iPhone is a 3.5in, patented touchscreen that controls all functions. This is advanced stuff, something that will have other device manufacturers in fits.

Depending on how the device is held, the screen orients itself horizontally or vertically (it also has sensors to adjust its brightness based on ambient light) and displays all the usual controls, including a telephone keypad, a qwerty keyboard, contact lists and so on.

Besides doing away with the need for buttons, micro keyboards and styluses, the screen lets users do such things as pinch two fingers together to shrink an image; spread the fingers and the image enlarges. As one commentator noted: "It's like you're reaching in and manipulating the content."

As demonstrated, there are top-level screen icons for texting, calendar, photos, camera, calculator, stocks, maps (through Google), weather, notes and a clock. System functions are represented by four other icons at the bottom of the screen: Phone, Mail, Web, iPod.

Adding it up, you can reasonably conclude that this slick device could play a role in the enterprise alongside other smartphones – even though that doesn't appear to be the intent.

One hopes that the incumbents take the iPhone as a warning shot across the bow and start paying more attention to the user experience.