What has been your experience with the iPhone GPS? At times it's been able to pinpoint the room of my house that I'm in, while at other times it tracks off by 30-50 feet (still in a straight line though) with lags and drop outs (while I was walking outside with no tree cover/partly cloudy). Is it possible the GPS is getting faulty data from the network? Are there different power modes for the GPS that might allow for more accurate tracking than what Maps is enabling? I never used the location feature on the old iPhone, and it only sporadically works on my wife's T-mobile phone, but how much of a benefit is this over the cell tower triangulation? It seems to me with the specs of the GPS chip in the iPhone that we could have gotten an extremely accurate chip worthy of attaching to a decently engineered antenna. Is that not the case?