The Nokia N900 has generated quite a debate since its launch, both in our office and across the web. The main bone of contention is a surprising one; it’s over the description of the N900 as a smartphone.

That’s how we reviewed it at the back end of 2009 and generally, we gave it a positive review. Some, however, prefer to refer to the dumpy Nokia as a mobile, pocketable computer that happens to have the capabilities of a phone tacked on. One reader even went so far as to request it be re-reviewed in the light of this assertion.

I can see why and, to some extent, I concur. The N900 is used mainly in landscape mode, just like a laptop; it has a physical Qwerty keyboard, just like a laptop; the OS is Linux-based and can be used as you might a normal computer running a Linux OS – there’s even a terminal app so you can get your mitts dirty on the command line, and for enthusiasts that opens up a world of control that only the N900 can offer.

It’s certainly different and, for that, I like it. It’s snappy, deals with multitasking more efficiently than most, and the Linux-style approach appeals to my geeky side. But despite that, and its internet-tablet heritage, I hold no truck with the argument that it should be reviewed principally as a mobile computer.

Why? Mainly because Nokia is marketing it as a phone. Every time I get on train, I see billboards advertising Nokia’s shiny new flagship and its multitasking abilities, not as a pocket alternative to a netbook, but as a rival to Apple’s iPhone, RIM’s BlackBerrys and any number of Android-based handsets. On the Nokia website, the N900 sits alongside the X6, 5230 and 6700, and is labelled a “mobile phone”.

For that reason – and that reason alone – the N900 should be reviewed in the same company as these devices. People need to know that its apps aren’t quite as easy to install, that there aren’t many of them, and that its phone capabilities feel a little tacked on. They need to know that in most ways it isn’t as good as an iPhone or the best Android handsets, and that it won’t deal with email as well as a BlackBerry.

But I also disagree because the pocket computer argument assumes there’s no overlap between the world of computers and smartphones. And there clearly is a considerable area of grey. Take a look at all the leading smartphones on the market and there are plenty of similarities that can be drawn between them and traditional computers.

Smartphones can be extended with applications, in many cases storage can be expanded, you can connect peripherals and you can turn them to all sorts of different uses, from simple note taking to navigation and even computer remote control.

So is the N900 a computer or a smartphone? It’s a smartphone, of course, just one that dares to be different.