KEY POINTS:
As I write this, a new toy is sitting on my desk. It's the latest portable satellite navigation unit from TomTom, called the 720.
At $749 it's costly and, being fresh out of its wrapper, I haven't yet used it to navigate anywhere, but it's an indication of the functionality of the 720 that I've had a lot of fun with it already.
The 720 differs from earlier TomTom units, such as the One and XL ($599 and $499 respectively), as it can hook up with your Bluetooth cellphone and iPod to become a mini media/communications hub.
The phone function allows you to pair your handset, download your phonebook and answer or make calls using the 720's touchscreen and built-in microphone.
The iPod connection comes via a separate cable. Plug your Apple music player into the unit, and all your playlists and track information are available. You can play songs using a built-in FM transmitter through the car radio, or use the auxiliary audio jack.
I'm pretty sure the 720 will work well on the road because I've been using the smaller XL model for four months. It's pretty much become indispensable for business appointments and the odd open-road trip to new places. Being a boy, I didn't bother to read any of the instructions and neither did I need to - it's entirely intuitive.
Carmakers will tell you portable sat-nav units, such as those from TomTom or Navman, aren't as accurate as in-car systems because they don't have "dead reckoning", a link to the car's speedo, as well as a gyroscopic connection.
But, after my time with the XL, I'd say they're wrong.
I tried it against in-car systems on road-test vehicles and it was at least as accurate, and easier to operate.
It was particularly interesting to compare it with the Professional sat-nav set-up in a BMW X5, which uses the same Geosmart data set as the TomTom device. Again, the portable unit was easier to set and more useful; the mapping was more up to date.
The TomTom also provides a range of services and downloads on the internet, anything from novelty voices to new maps. You can personalise your unit with colour and images, download speed camera locations/warnings and add points of interest.
Real downsides? Nobody with a nice car wants a plastic box stuck on their windscreen, and the battery only gives you a few hours' constant operation, so you will probably have to plug it into the 12-volt supply.
Small it may be, but it's also a pain having to remove and store it each time you park the car.
All of those issues will be worse with the new 720 if you also choose to use the iPod integration. These are not minor annoyances - but nor do they diminish the impressive functionality of the TomTom technology.