Nokia is a giant in the mobile phone world, but it has never embraced touchscreen technology with any gusto. In fact, the Nokia N97 is only its second such phone - following on from the 5800 XpressMusic - in recent times.

You can see why, for where the non-touchscreen E71 and E75 handsets are a joy to use, the Nokia N97 is a huge disappointment.

The main problem is that the S60 variant of Symbian - the phone's underlying operating system - was never designed with touch in mind, and the few tweaks added here and there don't turn it into an iPhone beater.

Navigation is frequently counter-intuitive and inconsistent.

Rather than flicking a finger up in a list, as if you were physically manipulating it, you pull down in the same direction as a scrollbar; fire up the web browser, however, and it's the other way around. Getting to the dial pad is another exercise in mental gymnastics.

In most places in the OS, such as the main menu screen, you simply hit the green touch-sensitive pickup key. Do this from the home screen and you're whisked off to the call history page; it's infuriating.

And there's a litany of places where the finger-friendliness of the N97's home screen and context menus seems to have been forgotten. Try to change the alarm, say, and instead of manipulating settings directly, you have to tap the fields first, then alter the time or date.

Neither were we impressed with the new, customisable home screen. You can arrange the screen to your preference, and there's a range of modules available. You can choose to display newsfeeds, a slideshow of your photos or a Facebook widget, and many more besides.

These can all be dragged around and repositioned but, in traditional S60 style, the results are far from pretty and there's limited space for them. You can only squeeze in five items below the clock, date and profile selection button before you begin to run out of room.

Text entry ought to be where this phone excels. Push the 3.5in 360 x 640 screen to the right and it kicks up at an angle to reveal a Qwerty keyboard underneath. While this is better than the Nokia 5800 XpressMusic's touchscreen-only effort, the keys have little feedback or travel, so it's hard to know when you've typed anything.

And the layout is bizarre. The spacebar is as far away from being in a useful position as it's possible to be - in the right-hand corner - while the five-way directional pad is positioned on the left; useful for lefties, awkward for everyone else.

Ironically, a touchscreen keyboard would probably be more effective, as the N97's screen is sensitive and accurate, and gives feedback as you tap it. Alas, the onscreen Qwerty keyboard of the 5800 has been dumped, with just the number pad remaining.

Then there's the build quality, which, for a phone intended to be a flagship product, is nothing short of shoddy. The back is thin, flimsy and feels plasticky, the lock switch on the left doesn't feel well constructed and the screen hinge mechanism, most critically, relies on plastic struts (not metal), which doesn't fill us with confidence either.

Aesthetics are more subjective, but we'd hazard a guess that our review model's white screen surround trimmed with chrome and matte off-silver rear won't be many people's cup of tea. The black model is better, but still far from glamorous.

Elsewhere, the N97's list of capabilities is immensely impressive. There's a good quality 5-megapixel camera with dual LED flash, a huge 32GB of onboard memory, a 3.5mm headphone jack and good quality sound and smooth video from the phone's usable media player.

You also get an FM transmitter that allows you to play your tunes through the speaker of any handy radio - excellent for an impromptu party, or playing music through a car stereo.

Plus, there's the usual smorgasbord of smartphone technology, including GPS, 3.6Mbits/sec HSDPA, Bluetooth, Wi-Fi, an RDS FM tuner and a front-facing camera for video calls.

An ambient light sensor automatically dims and brightens the screen, the proximity sensor allows you to silence a call by flipping the phone over, and an accelerometer rotates the screen orientation without lag. You can even use the camera to shoot 30fps VGA video; just don't expect Flip Mino-rivalling results.

It's all the more disappointing, then, that way before you get to the no-stone-unturned features list, the N97's usability issues stamp their muddy great boots all over your nice, clean smartphone fun.

The unavoidable fact is that this phone's touchscreen OS is frustrating and confusing, and as a package it doesn't add up. Its mid-range looks and feel mean it can't challenge the likes of the iPhone or HTC's best handsets, and one of its key selling points - the keyboard - simply isn't good enough.