CLLocationCoordinate2D currentLocation = [self getCurrentLocation];
// this uses an address for the destination.  can use lat/long, too with %f,%f format
NSString* address = @"123 Main St., New York, NY, 10001";
NSString* url = [NSString stringWithFormat: @"http://maps.google.com/maps?saddr=%f,%f&daddr=%@",
                    currentLocation.latitude, currentLocation.longitude,
                    [address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
[[UIApplication sharedApplication] openURL: [NSURL URLWithString: url]];

NSString* url = [NSString stringWithFormat: @"comgooglemaps://?daddr=%@&directionsmode=driving",
                    [address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
BOOL opened = [[UIApplication sharedApplication] openURL: [NSURL URLWithString: url]];

    MKPlacemark* place = [[MKPlacemark alloc] initWithCoordinate: latlong addressDictionary: nil];
    MKMapItem* destination = [[MKMapItem alloc] initWithPlacemark: place];
    destination.name = @"Name Here!";
    NSArray* items = [[NSArray alloc] initWithObjects: destination, nil];
    NSDictionary* options = [[NSDictionary alloc] initWithObjectsAndKeys:
                                 MKLaunchOptionsDirectionsModeDriving, 
                                 MKLaunchOptionsDirectionsModeKey, nil];
    [MKMapItem openMapsWithItems: items launchOptions: options];

Class itemClass = [MKMapItem class];
if (itemClass && [itemClass respondsToSelector:@selector(openMapsWithItems:launchOptions:)]) {
   // iOS 6 MKMapItem available
} else {
   // use pre iOS 6 technique
}

NSString* addr = [NSString stringWithFormat:@"http://maps.google.com/maps?daddr=Current Location&saddr=%@",startAddr];
NSURL* url = [[NSURL alloc] initWithString:[addr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
[[UIApplication sharedApplication] openURL:url];
[url release];

#define SYSTEM_VERSION_LESS_THAN(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedAscending)

NSString* addr = nil;
if (SYSTEM_VERSION_LESS_THAN(@"6.0")) {
   addr = [NSString stringWithFormat:@"http://maps.google.com/maps?daddr=%1.6f,%1.6f&saddr=Posizione attuale", view.annotation.coordinate.latitude,view.annotation.coordinate.longitude];
} else {
   addr = [NSString stringWithFormat:@"http://maps.apple.com/maps?daddr=%1.6f,%1.6f&saddr=Posizione attuale", view.annotation.coordinate.latitude,view.annotation.coordinate.longitude];
}

NSURL* url = [[NSURL alloc] initWithString:[addr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
[[UIApplication sharedApplication] openURL:url];

[CMMapLauncher launchMapApp:CMMapAppAppleMaps
          forDirectionsFrom:[CMMapPoint mapPointWithName:@"Origin"
                                              coordinate:myLatLong]
                         to:[CMMapPoint mapPointWithName:@"Destination"
                                              coordinate:latlong]];

$server=$detect->isiPad()?"apple":"google";
$href="http://maps.{$server}.com/?q=..."

NSString *destinationAddress = @"Amsterdam";

Class itemClass = [MKMapItem class];
if (itemClass && [itemClass respondsToSelector:@selector(openMapsWithItems:launchOptions:)]) {

    CLGeocoder *geocoder = [[CLGeocoder alloc] init];
    [geocoder geocodeAddressString:destinationAddress completionHandler:^(NSArray *placemarks, NSError *error) {
        if([placemarks count] > 0) {

            MKPlacemark *placeMark = [[MKPlacemark alloc] initWithPlacemark:[placemarks objectAtIndex:0]];

            MKMapItem *mapItem = [[MKMapItem alloc]initWithPlacemark:placeMark];

            MKMapItem *mapItem2 = [MKMapItem mapItemForCurrentLocation];

            NSArray *mapItems = @[mapItem, mapItem2];

            NSDictionary *options = @{
        MKLaunchOptionsDirectionsModeKey:MKLaunchOptionsDirectionsModeDriving,
        MKLaunchOptionsMapTypeKey:
            [NSNumber numberWithInteger:MKMapTypeStandard],
        MKLaunchOptionsShowsTrafficKey:@YES
            };

            [MKMapItem openMapsWithItems:mapItems launchOptions:options];

        } else {
            //error nothing found
        }
    }];
    return;
} else {

    NSString *sourceAddress = [LocalizedCurrentLocation currentLocationStringForCurrentLanguage];

    NSString *urlToOpen = [NSString stringWithFormat:@"http://maps.google.com/maps?saddr=%@&daddr=%@",
                 [sourceAddress stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
                 [destinationAddress stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlToOpen]];
}

http://maps.apple.com/maps?saddr=%f,%f&daddr=%f,%f

http://maps.google.com/maps?saddr=%f,%f&daddr=%f,%f

    NSString* versionNum = [[UIDevice currentDevice] systemVersion];
    NSString *nativeMapScheme = @"maps.apple.com";
    if ([versionNum compare:@"6.0" options:NSNumericSearch] == NSOrderedAscending)
        nativeMapScheme = @"maps.google.com";
    }
    NSString* url = [NSString stringWithFormat: @"http://%@/maps?saddr=%f,%f&daddr=%f,%f", nativeMapScheme
             startCoordinate.latitude, startCoordinate.longitude,
             endCoordinate.latitude, endCoordinate.longitude];
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:url]];

- (IBAction)directions1_click:(id)sender
{
    NSString* address = @"118 Your Address., City, State, ZIPCODE";
    NSString* currentLocation = @"Current Location";
    NSString* url = [NSStringstringWithFormat: @"http://maps.google.com/maps?saddr=%@&daddr=%@",[currentLocation stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],[address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
    UIApplication *app = [UIApplicationsharedApplication];
    [app openURL: [NSURL URLWithString: url]];
}

/*In case the user does NOT have google maps, then apple maps shall open*/
[OpenInGoogleMapsController sharedInstance].fallbackStrategy = kGoogleMapsFallbackAppleMaps;    

/*Set the coordinates*/
GoogleMapDefinition *definition = [[GoogleMapDefinition alloc] init];   
CLLocationCoordinate2D metsovoMuseumCoords;     //coordinates struct
metsovoMuseumCoords.latitude = 39.770598;
metsovoMuseumCoords.longitude = 21.183215;
definition.zoomLevel = 20;
definition.center = metsovoMuseumCoords;        //this will be the center of the map

/*and here we open the map*/
[[OpenInGoogleMapsController sharedInstance] openMap:definition];