I don't agree with gp's dismissal, but the point about gps and coarse location was that continuously updating gps (for full 3m resolution) would be too taxing on the batteries -- not that gps resolution was poor.
Don't think that applies if parent was using google maps to navigate, though -- how useful would navigation be without correct and updated position? Not to mention wi-fi location, correlation with plus posts/check-ins etc...
[1] http://www.gps.gov/technical/ps/2008-SPS-performance-standar...