Butch, and all, since I mentioned it,/but not trying to sell anybody 
anything, as I don't yet have and use GPS,
here's a note from
the blind phones list,
re _some of the more well known gps choices for the IPad, IPod, and IPhone, 
Posted a little while ago, by Mike Arrigo <n0oxy
"Gps on the iphone can be quite accessible with a few apps. If possible, I
would suggest getting navigon and TomTom, they use different maps and may
work differently in different areas. Another app worth checking out is
motionx GPS. All 3 of these provide great turn by turn directions. For
determining where you are, the Sendero Look around app works well. The good
thing is, you can enter a destination in to one of the gps navigation apps,
then minimize it and use the look around app to determine your location. The
garmin navigation app is very accessible also, but it doesn't have a walking
mode with voice guidance which makes it rather useless for blind travelers."
HTH, Danny Dyer, Wb4idu.