You know when you see the cell phone company commercials and they are super proud of their network, but there are huge areas that aren’t covered. I mean if you live in a very developed area it shouldn’t be an issue, but many people don’t. Then there are cities like NYC where you have super tall buildings. These devices can’t determine elevation, in theory you could use this in conjunction with a Bluetooth connection to more accurately determine the location, but it’s not something I would bet my money on. I certainly wish I could though and I’m trying hard to figure this out. I’ll be keeping a close eye on these developments in the meanwhile.