The iPAQ's evolution is almost complete. The first signs came with the H1940, a Pocket PC that finally managed to be good looking, tiny and powerful - and it even included Bluetooth. But the H4150, while looking rather similar, makes the H1940 look almost Stone Age, with HP squeezing WLAN into the package, upping the processor speed to 400MHz and improving the screen still further.

Of these, WLAN is the most notable inclusion. Finally, there's a Pocket PC versatile enough to be used in the office to hook up to your network, browse the internet, connect via VPN (Virtual Private Network) to a base when in a Wi-Fi hotspot, and all the while offering always-on GPRS via a Bluetooth phone. The only downside for HP in releasing this device is that it limits the appeal of its own H5550 (September 2003, page 52) purely to those wanting fingerprint security and the expansion potential of jackets.

We had no complaints about the 266MHz Samsung processor inside the H1940, but the increase to a 400MHz Intel PXA255 chip will no doubt help HP when selling to people who like big numbers. We found it gave marginally better performance in our synthetic benchmarks and demanding apps like Internet Explorer, but battery times remained nearly identical: the H4150 lasted for just over four hours with the backlight on its lowest setting and Bluetooth activated - a few minutes more than the H1940. In general use, expect around three hours over the course of a week.

The screen is superb. Once again, HP leads the way over its Pocket PC competition, with excellent viewing angles, bright backlighting and natural colours, the latter being the main improvement over the H1940. Another more minor improvement is to build quality, with the battery cover fitting much more snugly. Bizarrely, the H4150 also feels more pleasing in the hand, thanks to its 133g weight, compared with the 123g of the H1940; purely psychological, but it lends this PDA a quality feel.

It's good to see that HP now also provides a slip case and a docking cradle, while the headphone jack is now 3.5mm rather than 2.5mm. There's still no jog dial, and the infrared port is at the bottom of the chassis instead of the left-hand side, but the five-way navigation button feels much more precise. Before, we sometimes found that pressing down when scrolling through an email accidentally activated the middle select button, closing the email.

But this isn't to say that this iPAQ is perfect. We expected 128MB of RAM rather than 64MB, especially as only 56.8MB is available for data and programs. What's more, there's just 2.85MB available for backups, which won't even cover some people's Pocket Outlook data. Fortunately, HP is more generous when it comes to bundled apps, with an excellent photo viewer and five points to spend at www.ipaqchoice.com

But what faults the H4150 has are minor, and no-one can deny that this is a phenomenal PDA. In fact, it has just one real problem: the price. Paying nearly $850 for a Pocket PC seems ridiculous when Dell is offering the Axim X3i (see above) for $699. As such, we can't imagine the H4150 flying off the shelves, or being bought in bulk by companies. But, if you do buy it, you certainly won't be disappointed.