According to Fox News, they said that if the US Air Force fail to manage & invest in the GPS satellites, in 2010 GPS may fail!!
Adui, i have just started to have some fun in GPS then they may fail?
Haha.. wont fail i think.. US Air Force needs GPS so much in their navigation..
Let me show u how GPS works in iPhone..
When u click the button on the lower left side, then ur iPhone will the satellite.. at least 3 satellites are needed to locate ur exact location..
So at first u can see a big round circle showing roughly ur current position..
And then if u wait a little longer, then they will show u ur exact location..
They blue DOT will show ur current position in Google map..
It is very accurate for my current location in JB.. showing the exact location of my house..
Oh GOSH!! then u all know where is my house liao..
And then if i choose to move to a place using the GPS navigation, they will show the route..
Haha.. but mind u, it is not 100% correct..
And the route may not be the shortest..
And i have never tried before when driving..
Last time i tried but fail because i cannot get the blue dot when i’m in the car.. so cant really do much 
you have to put your phone near the window. cos when i drive my mum’s car, she got stick the v-cool stuff or something similar to reduce heat/radiation etc. haha or you have to open your window :p
make sense.. my car also got.. hehe.. next time try n c.. wont be funny meh? haha..