Portable navigation devices, or GPS-based satellite navigation systems, have become one of the hottest consumer electronic gadgets for drivers – as shown by the frequency with which they are a target for thieves.

I have been a big fan of in-car GPS navigation systems from the start. Even so, I have learned over the years that it makes sense to prepare for a road journey by also printing out maps and directions from a web-based service such as Google Maps, Yahoo, or MapQuest as a back-up.