Of course, the P320's Bluetooth connectivity means you needn't completely forget the idea of using the phone for serious work. One of Windows Mobile Professional's biggest selling points is that you can create, edit and save Microsoft Office documents, and with the right add-ons, this phone can still be a powerful tool - though you may get a crick in your neck peering at that tiny screen.
Elsewhere the P320 is not the most powerful device, however. It's a quad-band GSM phone, so it'll work pretty much anywhere you can get a mobile phone signal, but there's no HSDPA - just GPRS. It has just a 2-megapixel camera with no flash or self-portrait mirror too. And though Windows Mobile 6.1 helps it a little, the core components aren't the quickest: the OMAP850 200MHz processor chugs occasionally when launching applications, and the 64MB of RAM isn't the most generous in the world.
It's not as bad as it could be, though; help is at hand in the shape of a useful extra application called Auto Cleaner. This allows you to force Windows to remove applications from the memory when you press the X in the top right of the Window, instead of keeping everything minimised and slowing the phone to a crawl. Usefully, you can set some apps up to be exempted from this regime, so you can keep Windows Media player running, at all times if you want.
There are other notable features, too, some added by Asus, some courtesy of Windows Mobile 6.1. The latter is responsible for the Getting Started Centre, which provides handy shortcuts to important setup items such as email, date and time, and Bluetooth headset. There's threaded SMS, again; a new WMP 6.1 feature that I wasn't able to test in my review of the pre-production MWg Zinc II last week. Don't expect anything swanky like the iPhone's speech bubbles - all Windows Mobile does is group messages to and from specific recipients, a bit like Google Mail - but it is a useful addition. Google Calendar sync has also been preinstalled, as has Voice Commander (speech dialling and phone control software), and some handy additions to the device's phone functionality in the shape of a call filter and profile setup and selection tool.
It all goes together to make a well-rounded smartphone that's just about the most pocketable Windows Mobile PDA phone you're likely to come across. Unfortunately, though, there's no getting around the fact that the P320's small screen makes using Windows Mobile Professional even more fiddly to use than it normally is. But if you don't mind getting the stylus out occasionally and want the push email and office document features of a Windows Mobile device without the bulk, it's a very solid option. And the inclusion of a GPS receiver in a device this small is just the icing on the cake.