The BlackBerry seems to be going from strength to strength at the moment, at least if device launches are a reliable indication. The 8820 is the fourth to hit this year.

Actually the 8820 isn't an entirely new device. It is a revamp of the 8800, a business-class BlackBerry that lacks a camera, and if you've seen that device then this one will look very familiar. Its black and silver casing and the large QWERTY keys, which are shaped with a curved bevel, are a direct port from the 8800. The same can be said for the miniature trackwheel that provides for navigation through items on the non-touch-sensitive screen.

If you are looking for a sleek and small device for your pocket then this may not be it. At 114mm tall, 66mm wide, 14mm thick and 134g in weight it is not overly large as Smartphones go, but it will challenge smaller pockets. Like the 8800 the 8820 has a GPS antenna built in and is pre-loaded with RIM's own Maps application. You can use these in combination for satellite navigation.

Where the two devices differ is that the 8820 is the first BlackBerry to have inbuilt Wi-Fi. RIM has been promising this for a while and at last delivers. The inclusion of a connection manager in the applications list makes handling this, Bluetooth and the GSM connectivity easy, as you can turn each on and off individually simply by checking a box.

We had no trouble at all hopping onto our wireless network for a bit of tariff-free Web browsing, but be warned that the BlackBerry 8820 is not good for standard Voice over IP. It does not have the SIP protocol built in that would allow this.

Instead Voice over IP capability is dependent on what your network has to offer thanks to the UMA protocol. In the UK the BlackBerry 8820 is currently only available on Orange, which does have such a service, called Unique.

RIM has been including music playback in recent BlackBerry devices and the 8820 is no exception. There is 64MB of built-in memory, which isn't a huge amount, but there is also a microSD card slot under the battery cover. This supports SDHC, which means it circumvents the 2GB card size limit that befuddles many other devices. Currently 4GB SDHC-compatible microSD cards are available and the future maximum size is 32GB.

The mobile e-mail on the BlackBerry 8820 is slick and can cope with up to ten POP addresses via the BlackBerry Internet Service as well as corporate solutions via the BlackBerry Enterprise Server. The BlackBerry 8820 comes with the software you need to synchronise it with Outlook on your PC if you are a standalone user, and software for managing music too.

The 8820 is not a huge leap forward from the 8800 and may appeal more to businesses than consumers because of its black colouring and relatively large size. But it is a very competent device and the addition of Wi-Fi will matter to some.