You can do this by obtaining the latitude and longitude from CoreLocation, and then passing that into the maps URL. You can mix and match lat/lon and street addresses, which is what I do:
Code:
CLLocationCoordinate2D currentLocation = [self getCurrentLocation];
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]];
This works on my iPhone (2.2.1), and I didn't need to add any dummy parameters to the URL. Just saddr (lat/lon) and daddr (address).
