[a_c_s]

You can use iGo, Tom Tom or Garmin without a data signal if you only want the guidance...Garmin, with data, can also provide traffic updates (like the Sprint Navigation program)...Don't recall the exact size but you might be able to squeeze on a 1GB, though 2GB or 4GB would be a better fit...I have iGo and Garmin on my 4GB card with room to spare for plenty of other stuff like my backup CAB files...btw, Garmin looks and works great on the Sprint Touch Pro...haven't used Tom Tom on this phone but had good experiences with that program in the past as well...I've read that Garmin has the best VGA interface and graphics though...