How about bluetooth? It would be great to connect the Ipod via bluetooth to the PowerBook when needed, and to be able to listen to iPod music via bluetooth headsets - which of course should be compatible with bluetooth cell phones! That way it would be possible to answer incoming calls without having to change headphones.
Further more - that would allow me to listen to iPod music together with my girlfriend, on separate headsets. Tech-romantic huh? ;-) The possibilities are endless..
Apple, the iPod Isn't Finished!