I had the 1st gen iPhone and didn't really expect too much from it - if it did anything well then that was a bonus! But I upgraded to the 3GS because of its boasting about "accuracy of GPS" and the compass and the rumoured TomTom app. But it's rubbish! When I'm at home it consistently thinks I'm 0.6 miles away and using the iPhone to follow in the car is utterly pointless. I also bought (for 59p admittedly) an app called "Find My Car". Brilliant in a big car park - or so I thought. Cos of the inaccuracy of the "GPS" it's completely pointless.