It seems like a simple idea but mobile phone makers have for years failed to come out with the perfect all-in-one PDA-mobile phone combination.
Nokia, Mitsubishi, Siemens and Handspring have all tried, and none has yet come close.
But European start-up O2 might just be the first to get things right.
The O2 xda runs Microsoft Pocket PC 2002 Phone edition, which does the job well and will be familiar to any Microsoft user.
Most of the software is integrated with the phone. You can dial a number directly from the Outlook contacts database, as well as send an SMS or e-mail.
The setup required to log on to the CSL network in general packet radio service (GPRS) mode was minimal and it worked first time. CSL claims the speed is 40 kilobits per second though it feels slower. Then, it was a simple matter of configuring the Inbox to access my Netvigator account and I was up and running.