Google Maps Mobile Rocks!
I am using GoogleMaps on my blackberry curve. I don't have a GPS, however, I find the tower based location pretty usefull. Now I am in Paris, and for kicks I tried to use the future here. Well, to my surprise, Google Maps correctly found me in the middle of Paris with accuracy of 1700 meters. That's pretty damn close. This app rocks!!! If you still don't have it, get it at http://maps.google.com/mobile/