HP's iPAQ 312 is a strange device. Fitting somewhere between a PDA, a GPS and a mobile phone accessory, this unit packs in GPS functionality with some entertainment tools and Bluetooth mobile phone connectivity to create what HP has dubbed as the 'Travel Companion'.

While it doesn't have a specific niche, some of its features are quite well implemented. It is clearly designed with GPS functionality as the primary purpose, and HP has done a great job here.

It is simple to create a route; you can navigate to a specific address, stored favourite, point of interest, specific point selected on the map or even via GPS co-ordinates. Furthermore if you synchronise your outlook contact list with the iPAQ 312, all your contacts will automatically be selectable too.

The maps come with 2D or 3D views and are colourful and easy to navigate. This unit uses HP's own mapping software along with a SiRF GPS sensor. It typically took 30 to 45 seconds to acquire a signal, and reception was fairly good once it was obtained. Featuring a full touch screen interface, everything is extremely easy to navigate.

You can switch between the two views seamlessly, although we found the 3D view lagged a little, especially when you zoom in. Meanwhile the voice commands are loud and clear. You have 10 English voices to choose from and a variety of foreign ones too.

Our two main complaints with the GPS functionality were that the 600MHz processor is at times too slow to handle the application and we experienced a bit of slowdown and several crashes. The other issue was that many of the icons on the map page are unlabelled and extremely unclear as to their purpose.

Aside from GPS, the unit's other key feature is Bluetooth connectivity with your phone. Acting as a standard handsfree kit, the iPAQ 312 allows you to accept and reject calls via the touch screen interface. During our tests, both incoming and outgoing audio presented a slight echo, but it was of perfectly serviceable quality for a telephone conversation.

The 4.3in display itself is also extremely noteworthy. With a resolution of 800x480 and 65k colours, it is a fantastic little LCD and the image quality is extremely high for such a device. We watched several videos on the unit and were very pleased with what we saw. The touch interface also operated flawlessly and even our big fingers had no trouble inputting addresses and numbers.

That said the slowdown experienced when using the GPS was much more obvious here. Multiple times during video playback the sound stuttered or cut out all together, making this feature largely useless in our books. On the other hand the audio player was fine for casual use; it offers basically no features, but the 3.5mm headphone jack ensures you can use whatever headphones you please. File transfer is a standard drag and drop affair, and the player supports all Windows Media Player formats including those with DRM.

Other minor features of the iPAQ 312 include a clock, calculator, games and the aforementioned contact synchronisation. The games are mildly entertaining but nothing noteworthy, but the contact book works well, allowing easy synchronisation with your Outlook contact list.

Battery life was definitely a concern. We barely got several hours use out of the device on a full charge, so an AC connection is basically a requirement. The iPAQ 312 comes with 128MB of memory onboard and an SD-HC card slot for further expansion.