Google Earth, Google Earth Plus

The best Google-supplied layer that's fully functional in the UK is the roads layer. Although surprisingly comprehensive, it's not up to road atlas or A to Z standards: we saw numerous instances of small side streets being marked and labelled with the correct name, when larger roads nearby were either not marked at all or not labelled.

Elsewhere, the Local Search box theoretically allows you to find facilities, such as restaurants, based around your current location on the map. We found it patchy though; for example, it failed to come up with most of the restaurants in the area local to PC Pro's offices.

The Directions feature is better. Again, we found it patchy, sometimes failing to come up with anything, but when it works, it works brilliantly. Enter two locations and it will calculate the route between them. This is, of course, exactly what several online services such as theaa.co.uk already do. What they don't do is overlay the route with waypoints (such as 'turn left at The Avenue') marked on a scrollable, flyable aerial view, which is better than any normal map for getting an idea of what a journey entails. It's very generalised, though, coming up with a route but not necessarily the route you'd want; there's no ability to customise your preference for, say, cycling as opposed to driving and it doesn't know about things like railway stations; there's a specific layer dedicated to railway routes, but again, clicking on it currently only has any effect if you're viewing a region in the US.

For a $20 fee (about £12) you can upgrade to Google Earth Plus. The immediate benefit of this is faster network access, allowing much quicker image-data updates as you zoom in on a particular feature. The second benefit is integration with handheld GPS devices, although it's not as integrated as it might be. There's only the choice of downloading data from the GPS unit, not vice versa. A simple dialog box allows you to configure the client for Magellan or Garmin units, and pulls all of the data from the unit. You can then overlay the data, with your named waypoints, plus both tracks (ground you've actually covered in the real world) and routes (paths that have been programmed into the GPS in order to follow) overlaid on the map. It's fun to see where you've been, but very annoying that you can't upload routes calculated by the Directions feature to a GPS. It's also not currently possible to overlay your position on the map in real-time.

Bear in mind that none of the GPS import features are new; most mapping applications, such as Memory-Map, support the download and overlay of tracks, routes and waypoints and, more importantly, the upload of routes you've plotted. And of course, navigation software such as TomTom gives you real-time positional information.

There's no denying that Google Earth really is a minor miracle, truly harnessing the power of modern computers and high-bandwidth connections. At the moment, though, it's not actually very useful for UK residents. But the thing about it is, you know it's only going to get better. The Google Maps system (http://maps.google.com) is already being used to integrate geographical data from hundreds of sources and lots of effort is being made to bring that to Google Earth. This is an application with the potential to be the most important development on the Internet since the Internet itself.

Author: David Fearon