While the Sony Ericsson P990i bears a strong resemblance to its predecessors, this phone is a significant improvement on earlier P series devices. The P990i has a sleek curvaceous design that in many ways recaptures the values of the original P800, even if the design is somewhat constrained by the large QVGA screen and QWERTY keyboard that dominate this phone's front panel.

The Sony Ericsson P990i retains the P series' hallmark 2-in-1 style, offering a PDA ("pen style" in UIQ parlance) and keyboarded ("softkey style") phone interface. The phone "flip" keyboard is detachable, which helps reduce the P990i's size, but at the penalty of loosing a highly functional alternative interface.

The flip keypad now includes a 5-way navigation control in addition to send, receive, clear, and back keys. This makes the P990i a breeze to use single handed. While this sounds great, the flip closed mode does require a little extra effort by developers to make it the equal of the pen style interface, as some applications will not automatically run on both interfaces.

UIQ 3 offers two basic interface styles (although, as the M600i has already shown, there are is more than one way to implement them). These interfaces are: the pen style interface that employs a touchscreen, where a stylus is the principal navigation tool, and the softkey style keyboard interface, where a 5-way navigation and associated keys are the principal navigation tools. Both of these interfaces run on a QVGA (240 x 320-pixel) screen. However, the softkey style interface also offers a 240 x 256-pixel screen implementation, the flip closed mode.

So unlike earlier P series phones, the flip closed mode is now a part of the UIQ platform. This means it is relatively easy to extend an application built for the QVGA screen to flip closed mode, using the standard UIQ UI framework. To do this, C++ developers simply need to define UI "views" within their application for flip closed mode.

Java MIDP developers can create applications that work in flip closed mode using the sizeChanged method or by explicitly querying the size of the Canvas. However, Personal Profile developers are restricted to using only flip open mode.

Basic information on handling the flip modes is provided in a set of three guideline documents published by Sony Ericsson: Developers' Guidelines - UIQ C++, Developers' Guidelines - Java ME CDC, and Developers' Guidelines - Java ME CLDC. The C++ and CDC documents are also available in Chinese.

As a result not all applications support the P990i's flip closed mode. This fact is illustrated by comparing the menus in the two interfaces where, for example, the flip closed version of the Office menu lacks Quickoffice, PDF+ and the business card scanner.

The P990i is principally a business phone. In addition to messaging, email, and PIM applications it also includes the just mentioned Quickoffice and PDF+. Quickoffice enables the viewing and editing of Microsoft Word, Excel, and PowerPoint files (although PowerPoint editing is limited). It is also possible to run PowerPoint presentations through a Sony Ericsson MMV Bluetooth Media Center or iGo Pitch Duo, a handy feature that eliminates the need to carry a portable PC.

Given the P990i's business focus it seems strange that, unlike the M600i, the "today" screen is hidden. In both interfaces it is accessible from the main screen using the "block" icon.

This seems particularly strange given the large amount of empty space in the full main screen. The only other information this screen displays is for any playing music track or cell broadcast messages. However, this arrangement was probably chosen to make the two interfaces similar, as there is no space to add "today" information to the flip closed idle screen.

The P990i is however so much more than a pure business phone, this is because (amongst other reasons) it has one of the best camera interfaces seen on a Symbian OS phone. For example, the stills camera includes the ability to adjust the EV by up to 2 stops directly from the camera interface and thus compensate for backlit or frontlit subjects. The auto-focus and shutter release are fast and responsive, unlike recent implementation on other Symbian based cameraphones where these features are slow and laborious. It should easily satisfy most casual photographers and even starts to deliver the features that those with aspirations towards serious photography will appreciate. Added to which it takes sharp pictures with good color rendition.

The only real drawback to the P990i as a camera is that its display is a little hard to see well in full sunlight, but this is a fairly common problem with cameraphones. In most normal "phone" situations the screen is clear, bright and easy to read.

The video capability is impressive too. The results are still far short of those achievable with a camcorder, somewhat blurred and jumpy, but perfectly acceptable when the convenience factor is taken into account.

There is one aspect of the camera that is slightly mystifying; why it was necessary to add a LED indicator next to the shutter button to indicate that the camera is initializing? It seems such a fairly trivial function for a dedicated indicator.

The still and video capabilities of the P990i really lend themselves to a Cyber-shot based UIQ phone. If one is not in the works it certainly should be, as this camera measure up well to the stand alone variety. The camera is also an opportunity for developers, as this feature is not currently available on any other UIQ 3 phone.

While the capabilities of the P990i's camera may be a little lost on many of its business users, it does have one exceptionally good business use in the somewhat prosaically named "business card scanner". This application neatly eliminates the inconvenience of accumulating piles of business cards which, one day, you will get around to entering into your contacts list. The application is elegantly simple. You capture an image of the business card, check it looks OK and process it to create a record in the contacts database. In good light the accuracy is impressive and only minor corrections are needed in the worst cases.

WiFi makes its first appearance on a UIQ 3 phone on the P990i. One of the drawbacks of WiFi on smartphones can be its power consumption. Sony Ericsson seems to have cracked this issue on the P990i. Running the phone all day with scheduled email downloads every 10 minutes does not seem to significantly add to battery usage, nor do significant periods of Web browsing seem to cause the P990i's battery much concern. Overall the battery life is good, providing a good two days of normal use.

WiFi is not part of the UIQ 3 platform, but will be in later releases. To create applications that explicitly use and manipulate a WiFi connection requires the P990 Extension Package for the UIQ 3 SDK for the UIQ 3 SDK, available from the Symbian OS Docs & Tools page at Sony Ericsson developer world.

While WiFi will certainly appeal to the P990i's business users, there is another feature, which like the camera, begs for the P990i to find a wider audience (which it undoubtedly will). This is support for OpenGL, with hardware graphic acceleration. Vijay Singh Pro Golf 2005 3D, one of the two games delivered with the P990i, uses this feature. It is perhaps not the most impressive showcase for what should be a real bonus for games developers.

The P990 also has some nice little touches, such as the dedicated keylock button. While initially the need for dedicating this function to its own button was not clear (after all the same functionality is achieved with a long press on the M600i's back button when in the home screen) the added advantage of being able to lock the phone on a particular application proved invaluable.

There is also a dedicated media key that allows music to be started and stopped, or remapped to start the P990i's built in FM radio.

The P990i does however have a few inconvenient features. Sony Ericsson provides a PC application called Disk2Phone that allows audio on a PC or CD to be transferred to the P990i. However, this application works by copying audio files to the P990i when it is connected in File Transfer mode. To activate this mode it appears to be necessary to explicitly set it before connecting the device, the ability to choose the connection method at connection time would have been a useful feature.

On the subject of USB its worth noting that the P990i can be charged via the USB port, a handy feature that saves having to carry the charger while traveling.

While the P990i still has a few wrought edges, overall it is a very impressive piece of technology. Both interfaces are comfortably familiar, offering quick and easy access to the power of this device. Its robust set of business applications with the added features of a highly functional camera and well integrated music player and radio, should appeal to both business users and consumers looking for excellent all round performance and features.

For developers the P990 offers the challenge of creating applications that work in both the flip open and flip closed modes, to give users the greatest flexibility in using their P990i. The use of a pure UIQ interface in both flip open and flip closed modes should make this relatively easy. Features such as WiFi, a camera and OpenGL support opens up new possibilities for applications. Given the way users of the earlier P series phones have snapped up software, the P990i should offer a winning formula for third party developers.

For more information on developing for the P990i visit the Developer World P990i product page and check out the phone white paper. More information on Symbian OS UIQ 3 development and Java CDC can be found at www.sonyericsson.com/developer/symbian.

For developers new to UIQ 3 the papers "Getting started with Java ME CDC development" and "Porting to UIQ 3" are well worth a read. While for those who have already started working with the M600 may want to check out detials on the differences between the M600i, W950 and the P990i.