It may be the only innovation, but the ‘optical navigation button’ is impressive and we wouldn’t be surprised to see others copy it. It looks neat against the mostly black, shiny casing. At first glance you would think it is too small to provide a D-pad-style control. But, because you can slide the whole tip of your finger across it, the button has huge reach.

We found it was easy to move around the full screen, and when you want to select something you simply press down. HP has got the touch sensitivity just right and, because it is touch-sensitive to the finger, no object in your pocket can accidentally brush it.

We also like the overall look of this smartphone. The buttons are very minimal; on the front there is just the optical navigation button, a bar that contains almost invisible call and end keys, and the touch-sensitive menu and OK buttons.

iPAQ Data Messenger - ringer on, ringer off

We were impressed with the hardware button on the top of the casing, which turns the phone ringer on and off. This is not exactly unique (Palm has been offering the feature for ages) but we cannot see why it is as rare as it is.

There are some things we do not like. HP is aiming the handset at business users, and still thinks they do not want a 3.5mm headset jack. We hope they opt for the 3.5mm, instead of the 2.5mm, next time.

We were nonplussed by the absence of a front-facing camera for making two-way video calls, as on a 3G device with HSDPA you should be able to make a video call.

iPAQ Data Messenger - it’s all about the data

You will have noticed the word ‘data’ in this smartphone’s name, so it is no surprise to find a full QWERTY keyboard under the screen, which slides out of the right side of the casing.

The keyboard is not the best we have seen, nor is it the worst. On the downside it lacks a dedicated number row and, while the dollar and euro signs can be found on the keyboard with Fn key combinations, you need to go into the symbols menu if you want a pound sign.

We found we were able to tap out text messages and emails well enough, but not with the speed or assurance we have experienced on other similarly designed smartphones.

iPAQ Data Messenger - the verdict

The iPAQ Data Messenger will be available exclusively at Vodafone, then it will be available SIM-free. We think it could make quite a splash.