Offline Google Maps used to be called "Microsoft Streets & Trips"
FWIW, more and more phones are becoming GPS units, especially if they can run Google Maps (mobile).
You're right....GPS-enabled navigation devices are quickly becoming a commodity. I think Garmin lacks a sustainable competitive advantage. The United States Department of Defense controls the satellite system that enables GPS technology as we all know, and Garmin licenses maps from NAVTEQ (Nokia owned). Basically, Garmin delivers value by combining these technologies to a user-friendly consumer package that most of use to help assist in routing our special motorcycle routes or whatever activity you engage that requires GPS technology.
More cellular phones as you suggest threaten to displace stand-alone portable navigation devices like our Garmins. As converged devices (cellular phones that offer GPS-enabled features) continue to improve, consumers have less motivation to spend additional money on a separate GPS. That is why Garmin is trying to get in the game with the Nuviphone, but review of the early version faired poorly.
For me though, Garmin has the extra features that make it work quite well on motorcycles. I don't think I have seen many fellow riders using GPS enabled cell phone for navigating. For one the screens are small and if you go outside the roaming area etc, you are going to pay for the it $ sometimes.
With this free app, if your traveling in some small town with no net access or overseas, you can access Google Maps easily (just like using gmail with Google Gears for off-line use). There is of course:
OpenGTS - Open GPS Tracking System
But for most people, the Garmin system seems to work quite well.
BTW, just announced...the GPS system is going to get a major upgrade from the
US government.
For all those Libertarians that dislike government, they sure do love the GPS technology that enables them to enjoy their outdoor hobbies.
RB