GPS Data Logger Software - BT747

Don't know if this request belongs here, but with the new iPhone 3.0 it seems like it might be possible to access bluetooth GPS loggers. If so, I would love to have an iPhone app to download tracks to and also be able to access realtime GPS data from my iTrek Z1 logger. I have a first gen iPhone without GPS, but also I know that using even the iPhone 3G as a GPS data logger is not ideal, because:
- can't run logging in the background
- hurts battery life