Recently, my colleague Martin Veitch wrote in this blog about his favourable impressions of using Thus’s Mobile 3G Broadband modem with a laptop while away on a press trip.

Martin was enthusiastic about the technology, but found 3G coverage to be patchy. I have come to the same conclusion while testing out a couple of laptops for a future edition of IT Week.

The Dell Latitude D630 and Fujitsu-Siemens P 7230 are both equipped with built-in wide-area network capability, rather than relying on an external USB modem as Martin did. All that is required is to insert a SIM for a valid network subscription, and both laptops enable you to be connected to the internet from pretty much anywhere.

For my tests, I used a SIM kindly loaned to me by Vodafone, which fitted into the battery compartment in both of the laptops. In our central London offices, I was able to get a strong 3G signal and browse the web without being kept waiting.

However, outside London, it is a different story. I tried out both laptops at home in St Albans, just outside the M25 and about 25 miles from the centre of London. Here, it proved impossible to get a 3G connection, despite the fact that, according to Vodafone's coverage map, I should have been able to access the high speed (up to 1.4Mbit/s) HSDPA version of 3G as well.

This seems a shame, since it is users that live or work away from the metropolitan areas that might benefit most from a 3G subscription. In London, you never seem to be far away from high-speed access via a Wi-Fi hotspot these days, but that is not the case in many other places.