For people that are interested:
I have compared Navizon's pinpointing to Google's.
Navizon does a better job - this was on the AT&T network.
Navizon vs Google: http://www.doggunn.net/files/navizongoogle.png
Real Loc vs Google: http://www.doggunn.net/files/realgoogle.png
The other thing about Navizon is it works on the US T-Mobile network.
I am currently on holidays in the US, so that is not my actual address. Don't try anything stupid.