HP iPAQ hx4700

We need to get this PDA's problem out of the way right from the word go: it's big. Less of a palmtop, more of a handheld, the hx4700 is a Pocket PC that was never designed to slip discreetly into a shirt pocket. But before everyone starts decrying HP as a fool of the greatest magnitude, we should make it clear that there's a huge amount of compensation for the size.

The first, and most striking, is the screen. Measuring 4in diagonally, it dwarfs the 3.5in screens that we previously regarded as large - the effect is far greater than the extra 0.5in sounds. Equally important is the resolution HP squeezes in. None of that 240 x 320 nonsense, the hx4700 boasts 480 x 640 bright pixels.

Fujitsu Siemens' Pocket LOOX 720 also included a 480 x 640 resolution, but it compromised by using a 3.6in screen. The HP's extra space makes a big difference to readability; for instance, the Today screen appears huge, so you'll never have to squint to read an appointment. It's also handy when browsing the Web.

But HP goes one better again by including Pocket Informant 5 (see Mobile Computing), a program that will make you wonder how you ever lived with Pocket Outlook. Crucially, Informant takes full advantage of the larger viewing area. For instance, you can glance at your monthly schedule and see whether you have meetings in the afternoon or morning on any particular day; more contacts can be fitted on any one page, and are presented far more accessibly; and you can simultaneously search across your calendar, tasks and contacts.

As ever with its iPAQs, HP has opted for a quality screen too. The colours are vibrant, which means photos stand out, and the viewing angles are good enough for several people to crowd round the machine at once. But if you use the hx4700 only to display holiday snaps then you're wasting the power on offer.

A prime reason is the 624MHz Intel PXA270 processor. This doesn't make the hx4700 speed along quite as fast as we hoped: there's some minor stuttering when switching between applications, but this is due to the larger screen having to be refreshed. Certainly when we watched video it played back scenes smoothly, and searches were returned in double-quick time.

Another sign that HP is targeting the power user is the amount of memory on offer. There's the customary 64MB of RAM, but HP accompanies this with 128MB of flash memory - even if the battery dies, you won't lose any data if you store it here. In total, there's 85MB of flash memory set aside for storage, plus whatever you can steal from the RAM.

If you're willing to spend a little money, storage certainly won't be an issue. HP includes an SD card slot (which also supports MMC and SDIO cards) plus a Type II CompactFlash slot. The latter could be home to IBM's 4GB Microdrive, for instance, or a camera.

HP wasn't satisfied with all this, however, and decided to innovate even further. For this PDA doesn't feature the navigation pad we've grown accustomed to, instead opting for a trackpad. In two years' time, this will either prove to be a stroke of genius or a madman's folly - luckily, we think it's the former.

This wasn't our first impression though. In the default Navigation mode, the touchpad proved to be an unworthy replacement for the normal navigation pad. It's fine if you just want to press up, down, left or right, but if you try to activate a program by pressing in the middle of the pad then things get rather frustrating.