I found ZorroGPS on Internet. Since I am a girl whose sense of direction is not so good and ZorroGSP free trial lasts a week, I gave it a shot. It turned out to be very helpful for navigation. You guys could have a try.
ZorroGPS car navigation system sort of changed my life, given that fuel price is roaring. It always find me the best way and save me much fuel on the way. Sometimes, if there is traffic jam ahead, I will find another way with it. In a word, it is quite useful!