The Flybook is so small that it shouldn't even be mentioned in the same breath as other laptop computers.

When closed, it's only half the size of an A4 piece of paper, so the days of having to carry a large laptop bag around with you are well and truly numbered.

Considering its size it's a pretty powerful piece of kit. It has a 40GB hard disk, a 1.1Ghz Pentium processor and runs on the Windows XP Tablet Edition.

It even has a 8.9 inch touch-sensitive widescreen that enables you to navigate your files using the supplied stylus, which neatly tucks away into the side of the computer when it isn't in use.

Its best feature, however, is the slot for a phone SIM card. It accepts HSDPA SIM cards for a broadband-speed internet connection almost anywhere that mobile phone coverage is available. The connection is so fast that you won't need to search for a Wi-Fi hot spot ever again.

Obvious downsides are that prolonged use is difficult because the keyboard is so small and its control nub, which has more of a sand paper feel than some, but this is easily fixed with a notebook mouse.

At £1,800 it is also a bit expensive compared with its competitors.

Asus R2H, £700

The Asus R2H portable PC comes with plenty of features, including satellite navigation and handwriting recognition, but these don't compensate for the awkward design. A lack of keys is also a drawback as you need both hands to hold it.

Nokia N800, £280

Despite the Nokia badge you can't make phone calls on the N800. It is geared up for email and you can connect to the internet but, because the product doesn't come with the latest version of Flash, some websites don't load correctly on screen.

RIM BlackBerry 8800, Free with contract

The BlackBerry really kicked off the idea of accessing email remotely, and for this reason alone its latest model is world class. It does have 3G and GPS for the first time but is lacking in other functions.