The grainy picture doesn't inspire a huge amount of confidence in us though. TomTom would surely require Apple's help to correctly configure a tack-on GPS module for the device.
The concept isn't inconceivable though, especially with Apple opening the iPhone up to third-party developers in two months' time. If Apple's master plan is to make the iPhone into the ultimate personal device, GPS capabilities are surely on the list. The iPhone also has size on its side; its large 3.5-inch screen is the same size as many commercial satnav devices.