Map app for iPad that works while you're not connected to WiFi or 3G? About to drive across country and, while we're sporting iPhones, it sure would be nice if the navigator could use our iPad, non-3G, version to view maps while we're traveling. I've looked through the app store but the field is littered with impostors and the carnage of the poorly implemented.

Does such a thing exist? Is there a well-made, offline map app for the iPad?

Notes:


I'd need it to cover Canada (Eastern and Atlantic) and the North East United States (Maine, New Hampshire, Vermont, upper state New York).
Obviously I don't expect it to do any positioning (does the iPad 2 even have a GPS radio?) so an app that just called up street level maps would be fine. We're old enough to understand how to find our place in the world without a GPS lock on. :)
These apps might be of interest:


Galileo Offline Maps
OffMaps 2
Comparison of iOS Map apps


According to OffMaps2 library search, maps of New York, Maine, New Hampshire, Vermont and parts of Canada are available. 

Hope that helps, and enjoy your trip!