In my previous post I reported on my first steps with Google Maps Mobile on my Nokia E61i. I reported that I had to turn of my 3G network. I think this is for a part true, however this morning my train was re-routed on a different track due to some problems and I was looking into the route I was traveling without having 3G turned off. It looks like that if your travel along a GPS tower it will take this as a location point and it will skip all those UMTS towers. UMTS has precedence above GPS on the cell network. So it will depend on your location and the towers surrounding you if you will get a location or not. I still do not know if google simply did not index UMTS towers or that the 3G signal is not working with the application. However, I will be able to get my approximate position anyway I only have to turn of 3G from time to time.