Google Maps Navigation for non root users
See this post for new hack because old hack doesn't work anymore => http://www.2030.tk/new-maps-navigation-hack
Howto Enable Navigation outside US if you don't have a rooted phone?
Until now, just root users have been able to use Google Maps Navigation outside US but thx to TAPP (The Anonymous Perfect Patcher) non root users can install a special version of Maps and use Navigation...
See this thread on XDA for more details.
You can get the patched apk from this link, or see XDA Thread for updated mirrors, thx to brut.all to apply the patches from TAPP and putting the final APK's into space ;-)
Of course, the downside of this method for non rooted users is, that they have now 2 identical Maps application and just one of them will work.
For easy starting of navigation, take a look at this post.