We have had good luck with Android devices: phones and tablet. I find it very useful to create my own google map working from my desktop. It's one click to export a KML. It's a tiny file and I just email it to myself and SR. It works seamlessly with
http://www.backcountrynavigator.com/. I think I paid $9.99. The developer is responsive and has been updating. We use the app on both of our phones and our 7" Nexus tablet.
All of this works fine without 3G connection. You download topo or aerial maps within BC Nav while you are at home on your WIFI. We find it handy that SR can view the route on her phone, while I might fiddle with the tablet, since all devices can use the same app/data. It's redundancy, when the battery gets low on one device, we have another.
Just tonight I was looking at my 15" laptop screen showing highlighted roads and landmarks I have annotated in google maps, while comparing it to my 5.5" phone screen which was displaying USGS topo with overlay of USFS/private/BLM boundaries, and the same highlighted roads/landmarks from the imported KML. It makes it very easy to cross reference, and is not as complicated as it sounds. It really helps me dial in boondock spots when I go to satellite view. It's almost like cheating.
Experimenting with my new phone I notice that My Tracks (default app on my system), offers to 'share' to google, which means I can record any route, hike/bike/drive and record all the stats (distance/elev/avg speed/ max speed). When I export to google, my route is now saved to a google map, where I can see it on my desktop, email it to a friend, etc. You need a google account to use this feature. In my experience, the My Tracks app is easy, free and plays well with gmaps. BC Nav does not upload recorded tracks yet, to my knowledge.
These are all android based systems, as a comparison to the ipad method. Both use built-in GPS and offline mapping. Very cool.
I like the android/google package right now (devices used: Motorolla Droid2/Droid Global, Nexus7, Samsung Note2).
These are exciting times to explore with better mapping than ever IMHO.