BlackBerry maker RIM (Research in Motion) is pushing sales on two fronts, continuing to keep business and enterprise users happy with its heavyweight BlackBerry 8800 range while simultaneously pumping out more of its consumer-orientated Curve devices.

According to a Palm briefing we attended earlier this week, it needs to fight on all fronts, since sales of handsets that run on Microsoft’s Windows Mobile platform are increasing at twice the rate of RIM's BlackBerry range.

RIM is fairly churning out BlackBerry handsets this year. The BlackBerry Curve 8310 looks and feels the same as the Curve 8300 which came out in June. However, where that handset lacked built-in GPS, this handset has satellite navigation as its distinguishing factor.

PC Advisor had a sneak peek at the BlackBerry Curve 8310 earlier in the week before the all-important satellite navigation element was yet active, so we could do little more than play with Google Maps and some of the other applications that have now become integral to the BlackBerry Curve line-up. We’ve since tried out the Vodafone Sat Nav feature – a useful addition that handset owners will find a real boon.

Vodafone can’t take all the credit for the success of the Sat Nav feature. It’s sensibly bought in a proven third-party application from Telmap. Using this and the BlackBerry Curve 8310’s integrated antenna, we were consistently able to pick up six or seven satellites and get pretty precise location information, right down to the door number.

In the past, we’ve tried out satellite navigation features on mobile phones and found ourselves waiting aeons to current location details to be calculated – not useful if you come out the Tube station and need to thread through the back streets of London for an appointment.

We were therefore pleasantly surprised to find both Google Maps and Vodafone Sat Nav on the BlackBerry Curve 8310 pinpointed our current location within a few seconds, even when we were walking briskly along the South Bank. The Vodafone-branded navigation software has the edge on Google Maps and for those unaccustomed to the way BlackBerry menus work, is easier to get started with.

Click on the red arrow icon to launch Vodafone Sat Nav, then press Yes to allow Telemap to use its satellites to hunt you down. A screen offering Where To, Place/Business, Where am I, My places and Inbox then appears. Choose Where Am I to bring up a 2D map of your current environs and press the BlackBerry’s central navigational ball to display the address and geo-reference. Press again to save your current location, entering details such as the company name and number, if you wish.

For actual navigation, you can enter a town or street name or a postcode. We typed in the name of a London suburb and choose the Drive rather than Walk option for a particular hostelry. The BlackBerry Curve 8310 was ready to set off even before we’d grabbed our coats, almost immediately telling us to turn right out of PC Advisor Towers. Less than six seconds later it announced that it had finished downloading data for the complete route – admittedly less than 10 miles away, but necessitating some tricky one way routes through the City of London.

Directions are provided by a female with a clear voice and who sounds authoritative rather than bossy. Should you misinterpret prompts the BlackBerry Curve 8310 requires, you’re notified by a gentle ping rather than a loud and irritating error sound. As with previous satellite-navigation software we’ve tried on BlackBerry handsets, you move around the map using the numeric keys.

Google Maps takes noticeably longer to pick up a signal in heavily built up areas and defaults to showing relatively large geographical areas, although moving around the screen and zooming in and out is faster and easier. Press 0 to jump to your current location, indicated by a flashing blue ball, then move around the map using the orb (first introduced with the BlackBerry Pearl and common to all subsequent BlackBerry handsets).