Some analyst-type said earlier this year that Android will go on to become the most widely used mobile OS in the world by 2012. Some mocked, others debated and some, probably the majority, didn’t really care.

Nevertheless, the prophecy is being fulfilled by Android, and the Sony Ericsson Xperia X10 Mini Pro represents a newer – and significantly smaller – use of the Android OS.

So, how does the Sony Ericsson Xperia X10 Mini Pro do and, more importantly, is there much of a marked difference between the X10 Mini and the X10 Mini Pro? Besides the slide-out Qwerty keyboard, obviously.

As you’ve probably guessed from the name, the X10 Mini Pro is absolutely tiny. And when we say tiny, we don’t just mean small – we’re talking matchbox proportions, 90 x 52 x 17 mm.

Whether this is a good thing or not will depend entirely on the user. Unfortunately, for Sony Ericsson, this reviewer isn’t a massive fan of teeny-tiny handsets. After all, what’s the point of having a tiny smartphone? It’s rubbish for web browsing, you can’t watch videos on it very well and the less said about gaming on one the better.

Some users, however, prefer smaller handsets – and this is fine. But is the Sony Ericsson Xperia X10 Mini Pro a good mini-smartphone, or is it just a waste of connectivity and processing power?

Well, for starters the device is pretty good looking. It carries the trademark “Xperia” markings – a black, angular front panel for the uninitiated – and is pretty much exactly the same as the X10 Mini in terms of looks.

It is slightly thicker and, inevitably heavier, on account of the slide-out Qwerty keyboard, but this is a price we think everyone should be willing to pay as it is such a good addition to the device.

We’ve tested both devices and, while we don’t really like the micro-nature of the X10 Mini, the addition of a Qwerty keyboard on the X10 Mini Pro makes a hell of a big difference – it’s like a different phone!

Browsing, composing texts and email and making notes is an absolute breeze on the X10 Mini Pro. So much so, in fact, that in hindsight, we don’t actually know how we managed to function on the X10 Mini without one.

The keyboard itself is well designed and easy to use, the keys are slightly raised and well spaced.

During testing we became extremely proficient on it after only a short period of time and found that composing long emails was pretty straightforward – although, the text preview window is absolutely tiny, which is very annoying.

This is especially true when you want to check-back through a long email, but what can you expect from a 2.5-inch screen?

On board you’ve got everything you would expect from an Android device, such as Gmail, AndroidMarket, a decent media player and a whole host of other useful and easily accessed applications, which you can get to simply by flicking up the applications menu on any one of the homescreens.

Because the X10 Mini Pro is an Android device, you’ve got access to the aforementioned AndroidMarket, which means you can load up the micro-smartphone with apps a’ plenty. Unfortunately, there’s no Sense UI-esque layout and you can’t really fit any more than one app widget or short cut on the X10 Mini Pro’s tiny homescreens.

That said, you can have up to 20 homescreens, so you do have the option of spreading them out – just make sure you keep the less-used ones at the end, as that’s quite a way to swipe!

The X10 Mini Pro’s 5-megapixel camera is fairly decent, having both a flash and auto-focus. We found that taking snaps in both light and dark environments usually yielded pretty good results. However, the screen is so bloody small it’s actually quite difficult to judge the quality of your pictures until you’ve ported them over to a PC or Mac.

Possibly one of the most disappointing aspects of the X10 Mini Pro is that it uses Android 1.6, which is now, well, practically ancient. And this is made worse when you consider that some of X10 Mini’s direct competition, such as the HTC Wildfire, has Android 2.1 as standard – plus HTC’s unbeatable Sense UI.

For a little device, you can actually fit quite a lot into the X10 Mini Pro, which can handle up to 16GB via its microSD card slot. The accompanying media player that you’ll play your music through is also pretty good too, and this is definitely a big plus for the X10 Mini Pro.

Sony Ericsson has tried to spice things up on its Xperia range with the addition of things like Timescape, which consists of live tiles that relay all your social networking activity on your homescreen. To see what you’re friends have been up to, you simply flick through them and you have access to their tweets and updates.

We’ve seen Timescape before on the Xperia X10 and we didn’t like it then. But for the sake of the review, we gave it another chance. Unfortunately, we still didn’t like it and, if we’re honest, it’s even worse on the X10 Mini Pro because of its tiny screen.

The idea behind Timescape is that it gives you up-to-the-minute updates about what’s going on in your friend’s lives via their social networking accounts, which, we agree, does sound like a good idea…

However, in reality, this isn’t the case – there’s not enough detail at first glance, it doesn’t look good at all and to actually get anything out of it you’ll have to click on an update and open it up on the full screen to actually get the desired info, which kind of defeats the entire point of the application.

There’s also no support for Exchange or multitouch gesturing thanks to the Android 1.6 OS and, to make matters worse, you also get none of the speed optimisations that are present in Android 2.1 either, which, again, is pretty annoying – especially, when the device costs £250 SIM-free.

On the plus side, the 600MHz Qualcomm processor put in a very good performance during testing, allowing us to navigate around the device, open up apps and even play a few games with little or no lag at all.

Obviously, there’s a little latency here-and-there, but even 1GHz Android superphones still have issues with this, so we can’t be too harsh on the little X10 Mini Pro.

Overall, the X10 Mini Pro is a decent little phone. It’s not the best smartphone for browsing the web, sending long emails or watching videos on, but it isn’t a bad performer.

So, if you’re in the market for a very small Android device that won’t break the bank, you’d be hard pressed to find a better device than the Sony Ericsson X10 Mini Pro.

Recycle your phone: Sell Sony Ericsson Xperia X10 Mini Pro