If you have a Nokia mobile phone which offers A-GPS, you might want to use Nokia's Ovi map. Do you know why? It has turn by turn navigation for 70 countries and the best thing is that it is easily downloaded for free!!! How cool is that?
The only problem is that if you want to have all maps of 70 countries, you would need to have a large storage card on your mobile phone. I have a 16GB Toshiba microSD card and I would certainly hope that it is sufficient. Mind you, it includes turn by turn navigation!!! To know more about it, get on to here