Google Nav on the NC? 
http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=140934
Google is supposedly coming out (soon?) w/ an offline mode for GMN so you can preload all the needed data for your nav route while you have data access. Maybe I'll give this a try when that happens.
Probably not so great for everyday use, but might be nice for long-ish roadtrips... 
_Man_





