[Dean]

I did a lot of research on this because I do not have a data plan for my iPhone... I tested most every free app and scrounged data on all the pay ones.

TomTom, Navigon, etc have full base maps on device and can create routes, find POIs, etc. on the fly without data connection. MotionX-GPS Drive, Skoober, Gokivo, Waze, Google, MapQuest, etc. all rely in some way on on-line data access for map, routing, street names and/or other data, not just up to date POIs.

Some won't even fire up without a data connection, others will work from cached data but only if you already planned a route. Some can't create a route or display street names.

These also require that the Internet is up and their servers/site is up, not just a data connection. Servers apparently being an issue with some of the open source or smaller company apps.

Living in Nevada, any of those are objectionable to me. If I am near but not in Winnemucca, Lovelock, Hawthorne, Tonahpah or worse and get turned around and turn on my Nav app and it can't tell me what to do without a data connection, I am not a happy camper. Lot's of other scenarios, but you get the point.