Awhile back, there were several threads here on WB dealing with the importance---or non-importance---of maps.
Quite a few very experienced hikers sugested that on the A.T. they aren't necessary.
Some other folks stated that maps are ALWAYS a good idea in the backcountry.
People might want to check this out:
http://www.cnn.com/2006/US/12/06/mis...ily/index.html
It's a really sad story, and it provides a very grim picture of what can happen to you in the backwoods if you don't have a really good idea of where you are and where you're going.
Sometimes a cell phone is NOT enough and the cavalry DOESN'T get there in time.
And while this was in Oregon in winter conditions, believe me, it happens in the East, too, and sometimes in mid-summer.