Of course the Go 720 isn't just about map sharing - it's absolutely rammed to the gills with other great features too. It has a bright, high resolution 4.3in widescreen with a light sensor that dims and increases brightness automatically. It has automatic volume control that increases the volume of audio instructions depending on the amount of noise in the cabin. It'll not only tell you to turn right and left, but also has a text-to-speech engine that will read out road names and numbers to you as you approach turnings.
And if you're unhappy with the volume output of the excellent built-in speaker (unlikely), the Go 720 also has an FM transmitter in it so you can pipe the sound through your stereo. In theory this means you can use the TomTom as your in-car MP3 player (yes it has one of those too), and hands-free phone (using the integrated Bluetooth adaptor) and have everything running safely through your car radio. It'll even use its text to speech engine to read incoming text messages out to you.
In practice, though, I found myself sticking to the built-in speaker as the volume wasn't quite as strong as I'd have liked it. I had to turn the volume right up on my stereo in order to hear music and directions clearly, and this made small FM scratches and glitches extremely annoying. It's also a feature that isn't much use in dense urban environments where every inch of the FM signal band is swamped with hundreds of pirate radio stations vying for space. The Bluetooth features still work fantastically well in non-FM mode, but you'd have to use the headphone output to listen to your MP3 files on it effectively.
More impressive, for me, is the speech recognition engine, which seems to work well even with a fair amount of background road noise going on. I shouted Borehamwood, Sheffield and various address details while driving around the North Circular road in London and it picked up each one instantly, providing a list of options to choose from each time. Again it's not perfect - you still have to tap the screen two or three times to get to the voice recognition option, and sometimes if it doesn't recognise what you've said it pops out of voice recognition mode, but this is nitpicking. With a little practice it allows you to enter new destinations without having to pull over and off the road and that's a fantastic bonus.
You can even record your own voice instructions if you get fed up with the stock TomTom options. And this hints at another of the 720's excellent features - its customisability. Unlike most sat-navs you're not limited to what comes out of the box. Almost everything can be turned off or on. The screen layout, for example, can be changed so that information is displayed along the bottom or side of the screen. You can choose what information to display in that information bar. The automatic volume adjustment can be switched on or off, and the list goes on…