I had been thinking about this possibility too. Sort of make the N800 the user interface, while the phone acts as a cell/mobile gateway in my pocket/briefcase/backpack.

I'm also hoping that there's a way to work with the Agere BlueOnyx (bluetooth hard drive, similar to the Seagate D.A.V.E.). Similarly, the N800 would be the "user interface", and the BlueOnyx would sit in my pocket/briefcase/backpack and just store data ... like 40GB of mp3s.