The new Blackberry Curve 8310 is almost identical to the Curve 8300, with the only new feature being a built-in GPS receiver.

Our review sample was supplied by Vodafone, which has teamed up with Telmap to offer a complete satellite-navigation service. This is free for the first year, costing £39.99 per year thereafter.

The software is simplistic and doesn’t have anything like the number of features seen on dedicated sat navs, but there are some nice touches. For example, you can input a business type, such as ‘hotel’ and it will direct you to the nearest one.

Alternatively, you can input the name of a business or an address. Before the route appears, you’re asked whether you want to drive or walk; if you choose the latter, the system is intelligent enough to direct you along one-way streets which a car would not be able to use, but it won't navigate you through areas such as parks.

Route information is downloaded in one go, so if you lose your connection in a tunnel the Curve 8310 will still provide directions. Stray from your route and it will direct you back without having to reconnect, but only as long as you don’t go too far off course.

What hampers the sat nav, and indeed the Curve 8310 in general, is that it lacks 3G.This means maps take longer to update and tasks such as web browsing soon becomes tiresome. Wifi is also omitted. The Curve 8310 can handle Edge (only marginally faster than GPRS), but coverage in the UK is sparse at present and Vodafone doesn’t currently support it.

There’s still plenty to like about the Curve 8310 - it’s small, slim, has a Qwerty keyboard and, of course, is great for email. There are also decent multimedia features and even a 3.5mm headphone jack, but the Curve 8310 is certainly no substitute for a dedicated sat-nav device.