I don't know a lot about the architecture of the locator subsystem, but it would seem that it would not be terribly difficult to make the N900 emulate a separate bluetooth-connected GPS unit, while still leaving the location information available for applications in the phone. This would be useful for people who have to carry such units around, to use with phones or PDA's running navigation software not available on Maemo. I admit, not a very wide audience, but again, this doesn't seem like a terribly complicated application?