Not all towers in the US send back information in the same way for some reason...

I did something like this 4 or 5 years ago with a J2ME app. I used a standard query then parsed what returned to find the cell towers zip code. I then used that for simple location searches from a very infant Google at the time. I would think this app now uses the geo coordinates which also are reported.

The thing is, the zip code was not always in the same place in a string of returned information and as a result this approach was not very reliable in a small J2ME applet.

Perhaps this kind of thing is what is affecting this app in the USA. I would have hoped it would have been standardized by now.

BTW, sitting at home in Pennsylvania it was very fast. I'll be on the road toward Albany, NY tomorrow and will give it a go along the way.