iOS的GPS，

取得座標
locationMgr = [[CLLocationManager alloc] init];

locationMgr.delegate = self;
locationMgr.desiredAccuracy=kCLLocationAccuracyBest;
locationMgr.distanceFilter=0;

並於delegate實作
- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation

-(void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error

透過google的geo將地址轉為address
http://maps.google.com/maps/geo?q=地址&output=格式&key=金鑰

地址：如台北市民生東路XX段XX號
格式：xml or csv
金鑰：google api金鑰