Smartphone On Wednesday Apple will unveil its mysterious new iProduct, likely to be some form of e-book reader and multitouch multimedia tablet. The result could be a minor consumer tech revolution. But that's Wednesday. Right now, the personal computer exists in three main formats: the desktop PC; the laptop (including the netbook); and the mobile phone.

Netbooks qualify as laptops because, despite early promises of cuddly versions of Linux, there has been no real shift from the paradigm of an old mouse-led Windows operating system (OS) hampering a slow-boot mini PC. A netbook today is, in essence, a small, cheap laptop with no DVD drive. Everything else is lily-gilding - see our Nokia Booklet 3G review.

Desktop PCs are in decline and laptop sales are rising, a trend we'll see continue as people realise they don't need a hulking box to satisfy their computing needs. Follow that further, and even the laptop may soon look old-fashioned. Developments in mobile computing are gathering pace, whether or not the devices are held up to the face to make phone calls.

But beware the encroachment of advertising into the mobile computing space. There are Greeks offering some very tempting gifts these days - such as the manifold services of the world's biggest online advertising broker.

At the moment, Google et al are offering a lot of services ‘for free'. But you're paying nonetheless, usually with your eyeballs' attention being led to advertising that's focused to your interests. When you write emails to your family about renovating the bathroom, expect to see ads in your Googlemail inbox punting the services of plumbers. You may consider that useful, or an invasion of your privacy. But that's the price of Google's ‘free'.

Google's move into the mobile phone market - giving away its Android OS - isn't down to sheer altruism, either. We've recently reviewed the Google Nexus One and the Motorola Milestone, and once again find that Android smartphones demand you have a Google account to get them working properly. Once in Google's sphere, expect your mobile phone habits to be monitored and sold on to other companies. Your personal anonymity is assured by Google, of course.

And when smartbooks and tablets start to take off soon, don't be surprised if a new race develops: one to find new ways to advertise at you while you enjoy all that mobility on your portable PC.