CLLocationManager *locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyBest;
    locationManager.distanceFilter = kCLDistanceFilterNone;
/* Pinpoint our location with the following accuracy:
 *
 *     kCLLocationAccuracyBestForNavigation  highest + sensor data
 *     kCLLocationAccuracyBest               highest
 *     kCLLocationAccuracyNearestTenMeters   10 meters
 *     kCLLocationAccuracyHundredMeters      100 meters
 *     kCLLocationAccuracyKilometer          1000 meters
 *     kCLLocationAccuracyThreeKilometers    3000 meters
 */
    [locationManager startUpdatingLocation];

- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation
{
    MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(userLocation.coordinate, 800, 800);
    [self.mapView setRegion:[self.mapView regionThatFits:region] animated:YES];

    // Add an annotation
    MKPointAnnotation *point = [[MKPointAnnotation alloc] init];
    point.coordinate = userLocation.coordinate;
    point.title = @"Where am I?";
    point.subtitle = @"I'm here!!!";

    [self.mapView addAnnotation:point];
}