The geekosphere has sprouted clever laptops that fold up like origami. Rosemary Haworth reviews the newest machines



Tablet PCs are laptops that, though they come in a variety of guises, all have a touch-screen display in common. Built-in handwriting recognition software translates individual characters and cursive script into electronic type.



Convertibles, such as the three here, offer the most flexibility and let you flip or slide the screen between tablet and conventional notebook 'keyboard and screen' mode. Users of personal digital assistants running Windows Mobile 5.0, in particular, will find it easy to get to grips with using the text and graphic interface on a tablet PC. All the models here feature built-in wireless and Ethernet connectivity.



Acer TravelMate C202TMi

Sporting a 1.7GHz processor, an 80GB hard drive, a 12.1in screen, 512MB of RAM, a 64MB graphics card and an eight-speed dual-layer DVD writer, the Acer manages to cram in some great features for an eye-catching price. The sliding screen is a neat touch executed well, with a latch system you flick to glide between modes. One downside is that there is subsequently no wrist rest in front of the keyboard. There is also no touchpad (you get one of those directional pointing sticks instead), but there is a discreet scrollwheel to aid your passage through lengthy law reports.



None of this impacts on the TravelMate's performance - it is far faster than the ultraportable Fujitsu-Siemens machine and, though relatively bulky for a 12.1in model, a more practical proposition than the hefty Toshiba. Acer also includes its standard software-based encryption and external device locks, as well as other failsafes, each of which are accessible and configurable via a dedicated button.

Cost: £1,009 plus VAT

www.acer.co.uk



Fujitsu-Siemens Lifebook P1510

Fujitsu-Siemens claims this bantamweight tablet PC is the lightest of its kind. Not only is its 1kg easy on the arms and shoulders, the P1510's design is less awkward to transport than the other two tablets here.



Using the longer-lasting battery bumps the weight to 1.2kg, but this is still more than acceptable in return for up to five hours of use between charges. Security-wise, Fujitsu-Siemens has found room for a biometric fingerprint reader and, in common with both Toshiba and Acer, has software designed to keep intruders out.



Not everything about the P1510 is ideal. Processor speed is relatively limited - only a 1.2GHz Intel Centrino. But, since this a low-voltage processor, it gets decent battery life. For many mobile workers, this alone might clinch it. Another trade-off is that you have to do without a built-in CD or a DVD drive, though an external DVD writer does come with the package. More importantly, the Lifebook's tiny dimensions do help to keep the weight down, which means you have to make do with a 8.9in screen. This also means that the keyboard is rather small and you may not want to type on its fairly cramped keys for extended periods.

Cost: around £1,230 plus VAT

www.fujitsu-siemens.co.uk



Toshiba Tecra M7

Probably the most unusual of the three tablets reviewed, the Tecra M7 is a 14.1in widescreen model.



As well as immediately marking it out as a little different from most tablet PCs (HP also has a widescreen model), it means this is the heaviest of the three here at 2.8kg. Running Intel's new Centrino Duo dual-core processor, it is also the most powerful, at 1.66GHz. You get 80GB of hard-disk space, a memory-card reader and, like the Lifebook, fingerprint recognition. Toshiba also embeds a security chip inside the notebook, which means that if someone makes off with it, it can be locked remotely.



All this screen estate means the Tecra M7 cannot compete with the P1510 on battery life. Even so, you should find the Toshiba useful for around three hours. Since most people will not want to be forking out north of £1,000 plus VAT for a notebook for business use alone, it lends itself perfectly to relaxing with a DVD. Helpfully, then, Toshiba has tricked out the Tecra with a DVD+/-RW and DVD-RAM drive.

Cost: £1,099 plus VAT

www.toshiba.co.uk



How do the chips fall?

There is a whole range of takes on the tablet PC concept, and your choice will come down to whether you need the touchy-feely input on a regular or just occasional basis.



There are large differences in price depending on the processing speeds and applications you need and, if portability is the main criterion for you, you are likely to have to pay over the odds for a lighter model that may lack useful items such as a built-in CD/DVD drive.



In the round, the Acer offers the best combination of battery life, value, performance and portability, but either of the other two might be the best for your specific needs.



Rosemary Haworth is a technology journalist