Im running Tomtom5 on my sony ericsson P910i.
http://www.tomtom.com/products/categ...D=2&Language=1
Find a phone that can run Tomtom 5 mobile, you be much happier. Out of so many GPS software I tried nothing beats the Tomtom not even the PC based can touch it. Maybe NAVIGON Mobile Navigator 5 can get close to it but thats only for PDAs.
The Tomtom for phones run as good as the PDAs with same features, maybe just a bit slower but thats because the HW on the phones are slower.