Having the maps stored locally is only 50% of your battle - you also have to use a phone that uses satellites for GPS location. This is not something most phones do (the majority of phones use only cell towers).
Once again, incorrect.
A phone with a GPS receiver uses GPS satellites to determine your location. That's the whole point of having a GPS receiver. The GPS receiver does not need cellular/data coverage to determine your location. The majority of smartphones have GPS receivers. Check the specs for the device you're looking at.
The GPS
app may or may not require data. It really depends on the app. This is another area where people are commonly mistaken. Data requirements come from the app, not the GPS receiver. Again, if you have locally stored maps then you're good to go. Granted, if your app's other features (such as traffic, etc) require data then those features won't work while you don't have data but the point of having locally stored maps is so that you can navigate without data.
It's a common mistaken assumption that aGPS is tower triangulation. It's not. It's GPS. That's why it has GPS in its name. If you're not using the GPS satellites to determine your location then you're not using GPS. I know a lot of people use the word "GPS" to mean "any method of determining your location" but GPS has a very specific definition. aGPS is just assisted for a faster initial fix. It still uses the GPS satellites to determine your location. It does require coverage to download the assistance data but every aGPS receiver I've run across can fall back on standalone mode if the assistance data cannot be accessed. All that means is that the GPS fix will take longer.
GPS, of course, isn't the only method of determining your location. If GPS isn't available some apps will fall back on other less accurate methods such as tower triangulation, WiFi, etc. None of those other methods are GPS.
I don't have a list of phones that do or don't use satellites for GPS triangulation - but I know that most HTC phones DO use it.
Again, if they're not using the GPS satellites they're not using GPS. There's no such thing as "GPS triangulation without satellites". The satellites are the Global Positioning System.
Can you provide any examples of smartphones that ship without a GPS receiver?
Is there a way I can navigate through dead zones (no cell service) and keep my navigation app running? None of the offline solutions I have found actually say you can do this; they just say the maps are stored on your SD card and you don't have any data charges. I apologize if this has already been answered and I missed it.
Did you ever look at the web sites for any of the developers?
From
http://www.copilotlive.com/us/personal/android.asp
Detailed street maps of the U.S. and Canada* are stored on-board your Android device so there's no need to use your mobile service or data plan to navigate to your destination or worry about losing directions when you travel out of coverage.
https://market.android.com/details?id=com.navigon.navigator_checkout_us&feature=search_result
On-board navigation entails no data transfer or roaming charges, for example, for route calculation or map displays.
MobileNavigator Android is an on-board solution. This means that all map material, voice announcements and system files are saved on the telephone. Therefore no charges or waiting time for data transfer are incurred.
If in doubt, contact the developer and ask.
