The evolution of the PDA and the smartphone is in question at the moment. Phones are small and handy, PDAs are big and useful.

There's room for both of course, but there is a big overlap: PDAs have connectivity built in, and phones can do email and WAP browsing. Both hold calendar data. It is obviously logical for at least some people, to combine the two devices. But is the combined device a smartphone which acts like a PDA, or a PDA that can make like a phone?

The XDA II is definitely one of the latter. It is made by HTC, also responsible for several of HP's Ipaqs. It runs Windows Mobile 2003, and comes with a substantial 128Mbyte of RAM, and an SDIO card slot. It has built in Bluetooth and can work with a Wi-Fi add in card from the likes of Sandisk.

It is big and heavy of course: it weighs 190g, and only has a quoted 3 and half hours talk time (with a standby of 150 hours - that's less than a week). This makes it bigger and more power-hungry than smartphones like the Handspring Treo 600 (reviewed here). Both are absolutely trounced in these stakes by the less-fancy RIM Blackberry (reviewed here).

Although the device is clearly a PDA first, the phone is not merely a bolt-on. HTC moved the Calendar and Contacts buttons from the bottom of the screen to the top, so the two buttons at the bottom can be the usual Talk and Hang Up buttons of a phone. The mike and speaker are built into the right places, and work fine, even as a speaker phone.

The Bluetooth headset connection works well, which is good. O2 bundles a Bluetooth headset and, given the size of the device, users will probably find themselves gravitating to Bluetooth. If nothing else, this gives you access to the apps on screen, and stops you smearing it with your beard or make-up.

Dialling by stylus from the soft keypad works well, as does dialling from the address list.

The software includes Pocket Word, Excel and Outlook. O2 has also added a viewer for PDF and Powerpoint documents.

There is also what O2 calls the Active Today screen, which is a useful front end that lets you change settings very easily to make sure you can get your email, or do other tasks with one or two clicks. It is also easy to wipe out your email settings with one or two clicks until you get the hang of it.

As it arrives, the XDA's email client is separate from the inbox of ActiveSync. This is not intended as the main repository of your email - the mode of use is to deal with upcoming emails in your XDA inbox, then synch everything up with your main Outlook client on returning to your desk - or over the network.

There are also games, and through links from the supplied CD, it is frighteningly easy to download new games including backgammon, golf and, well pretty much everything. But the most compelling frippery is the built in VGA camera. It's pretty good of its type, and the big PDA screen makes an excellent viewfinder.

More useful, and easy to overlook is a well organised sound recorder. Both the camera and the sound recorder have special buttons on the left side, and it becomes quite natural to use the machine as both camera and recorder.

Normal data entry is by stylus, using the usual Windows Mobile data entry options - a soft keyboard or letter-by-letter scribbling. This is a meaty enough beast to manage the newer cursive recognition, which seems to manage my handwriting (and by implication can probably transcribe anyone's).

Turning the different radio modes on or off seemed a bit fiddly and unresponsive, but this may improve with practice. Press the radio icon on the top bar, and you get a menu box that lets you turn the radio on or off and turn on GPRS data. You have to wait a long while for response though. Bluetooth turns on and off smartly from the bottom bar.

Web browsing on a PDA screen as big as this (240 x 320 pixels) is pretty good, including use of forms and other fancy stuff. We used it to edit stories on the live Techworld site without any huge disasters.

The machine works as a wireless modem for your laptop - though you have to go install an extra driver on the PC to do this. The instructions in the manual are a bit shaky about how to do this. The feature appears to not work at all for Windows 2000 - though we suppose it is fair to assume that anyone with an XDA II is likely to have the very latest in desktop / laptop software as well.

OUR VERDICT

If you want a combination device, and lean towards a PDA rather than a phone, this is the obvious machine to get. It's an Ipaq-like PDA that is a very functional phone yet handles email and other applications smartly. For the money you could look at getting two separate devices though.