I don't use a device lock, but I can see that this might well be quite useful for some people. Expanding it to also control other aspects of the device when you're connected to a known network, or in a given location, etc., etc., and indeed we have one of those Nokia Beta labs ideas.

Yes, though this also requires a network connection atm afaiu, as the device does not have a local tower id to geographical location db. This is something that certainly could be added though, or even built up from visited areas (sounds a bit like an iPhone all of a sudden )

Is liblocation open though? I must check, as ideally one add the ability to use cached/local db cell ids to that api.