I'm not talking about cell tower triangulation, I'm talking about offloading computation to more capable hardware located remotely. It exists:
http://en.wikipedia.org/wiki/Assisted_GPS#Modes_of_operation
I can't find anything about chipsets that only do that, but I'd be surprised if nobody had ever done it.
I've used the iPhone 3G, 3GS, 4, and 4S extensively in the wilderness. Every version since GPS was introduced has been "real" GPS.