forgive my ignorance: but am i to understand that Ovimaps map data is streamed through your 3G connection, and not stored locally?

Does this mean that nokia makes a deal with local contract carriers to allow Ovimap data to stream to the phone for free?

Where does maemo-mapper come into this:
If Ovimap data is streamed, and the stream is considered outside usual data-plan charges, where does this leave PayG users?
Can mameo-mapper and locally cached cloud made maps replace Ovimaps for PayG customers?

Cheers