http://www.navigon.com/site/int/en/products/navigation_software/iphone

I play with this software all this day long... I'm happy.

It's a very good supplement to Google Map on my iPhone.

The company seems very reactive... I follow them on Twitter http://twitter.com/NAVIGON_ and Flickr http://www.flickr.com/photos/navigon/

Version 1.2 is coming soon http://www.insanely-great.com/news.php?id=10532

The car kit for iPhone seems good, too