Is it possible to get GPS coordinates without paying for data or ATT Navigator? I realize that free programs like Google Maps require data, but could I connect my phone to Google Earth on my computer with wi-fi and then use it to place coordinates on the map? The map data would come from wi-fi, so can I use the phone as a free connection for coordinates that my computer would place on google earth?
It would depend on the phone. Some phones do have stand-alone GPS units in them so can in fact communicate with the satellites and crunch a location entirely on their own. Most phones however, use assisted GPS (aGPS), which does rely on sending and receiving data from cell phone towers as well as the GPS satellites. The data may be timing data from the towers, or use their own GPS positions for trianulation, or it may download satellite data, but offload it to the carriers servers for computation of the position.
Bottom line is, if your phone is aGPS, then it will be using a data connection for some aspect of fixing a position, even if you are just using it to get the numbers to plot on something else.