Connected handhelds that are small but highly usable are hard to find. The XDA Mini S is admirable because it manages to combine both these features. This is mainly due to its clever sliding keyboard. This lets you get the most from its operating system and bundled software, which includes the likes of Pocket Word, Excel, PowerPoint and Outlook. It's certainly not without its faults -- the audio quality during voice calls is almost unforgivable for a handset of this sophistication, so if you spend more time talking than you do creating digital documents you may want to look elsewhere.
The 02 XDA Mini S is based on the HTC Wizard, the inspiration for many handsets, including the i-mate Jam. As a result, it doesn't look particularly 'mini' on initial inspection. It's only slightly larger than a pack of playing cards, but its 58 by 109 by 24mm frame looks distinctly chubby next to normal phone handsets such as the ultra-thin Motorola Razr V3.
Its relative bulk can easily be forgiven once you realise it's hiding a neat trick up its sleeve -- its screen slides horizontally away from the body of the handset to reveal a Qwerty keyboard. The orientation of the display then automatically switches from portrait to landscape, and you an use your thumbs to navigate through menus or enter text into the handset's various applications.
It's not essential to use the keyboard -- the XDA Mini S has a wealth of shortcut buttons scattered on almost every corner. There's an on/off switch at the top of the unit; camera and voice-dialling/application-launching buttons to the right; a volume control slider on the left; and four buttons on the front. Two provide one-touch access to Internet Explorer and the message inbox. The other two are context sensitive, changing function depending on where you are in the menu.
The screen measures 71mm (2.8 inches) on the diagonal and is touch-sensitive. The XDA Mini S includes the requisite stylus tucked away in its rear quarters. This impressive little tool extends with a satisfying, hydraulic-like action complete with whooshing noise. On the whole, the entire unit is aesthetically pleasing, with our only real gripe being the slightly plastic-looking outer casing.
The XDA Mini S is built on Windows Mobile 2005 Pocket PC Phone Edition. This is a versatile platform that has much in common with desktop operating systems like Windows XP. Most of the navigation is done via the Start menu button positioned at the top left of the screen. The device comes pre-installed with Mobile versions of Microsoft Word, PowerPoint, Excel, Internet Explorer and Outlook. Like BlackBerry handsets, the XDA supports Direct Push technology, which means your emails are sent directly to the handset -- you don't have to remember to log on and check for new mail.
The Qwerty keyboard makes a great accompaniment to the above applications, and makes entering emails a breeze. It lets you type messages and lengthy documents quickly and with ease. Unfortunately, there's no number pad, just a horizontal strip of numbers. This means dialling phone numbers can be a little unintuitive, unless you use the somewhat fiddly virtual keypad that appears on-screen.
Even more annoying is the lack of a shortcut key to access phone features. In order to make a call you'll need to use the stylus or Start button to access the Start menu, before clicking the Phone option -- hardly ideal if you're in a hurry. The XDA Mini S is a quad-band handset, and can therefore be used to make and receive calls in most countries.
The XDA Mini S has many connectivity options. USB and Bluetooth links are available, as is 802.11b wireless, and for those who refuse to let go of the past, there's an infrared receiver on the right of the handset. Disappointingly, this device isn't 3G-compatible, so you can't make video calls or surf the Web at near-broadband speeds unless you're connected to a Wi-Fi network.
The XDA Mini S comes with just over 47MB of usable storage space, with a further 44MB dedicated to storing applications. That's not much space to play with, so we recommend you buy an add-on miniSD memory card. This plugs into a slot at the top end of the handset -- which is a better arrangement than some mobile phones that require you to remove the battery before inserting a memory card.
In a world where 2-megapixel cameras on phone handsets are becoming more commonplace, the 1.3-megapixel offered here is a minor disappointment. It's still good enough to take the odd snap here and there, but it's a poor substitute for a dedicated digital camera. On the upside, images look great on the 240x320-pixel 64k-colour display.
Audio quality on the XDA Mini S during voice calls is poor. The sound is muffled and tinny in comparison to even basic handsets, and things get even worse when you're using it in poor signal areas. Its battery life isn't particularly bad: O2 claims up to five hours of talk time and 200 hours of standby time depending on individual usage, but you'll probably need to charge it nightly to avoid running flat unexpectedly. The handset can be charged over a USB cable, so you won't need to lug the three-pin mains adaptor around.
On paper, the device isn't particularly quick, but it works just fine in practice. It uses a 200MHz CPU, which is fine for running the applications it ships with. You may struggle to run some third-party programs, though. Skype for Pocket PC (a Voice over IP application), for example, requires a 400MHz CPU.
Edited by Mary Lojkine
Additional editing by Nick Hide