After lots of work, apparently--up to "six or seven" partner companies in the network infrastructure. All this engineering tinkering has resulted in an always-on Loopt iPhone app that runs in the background on the network rather than the phone. Presumably this has a knock-on effect on the precision with which one can be located (the background Loopt app isn't accessing the iPhone's GPS to find out where you are, and it's most-likely using cell-tower triangulation methods, much as Assisted-GPS units do to boost their location-sensing powers).