iTunes 4.7.1 introduces ‘Shadow Mode’

Scott Knaster, author of 'Hacking iPod + iTunes,'
discusses a new preference in iTunes 4.7.1. Basically it allows you to keep a place holder for your iPod shuffle in the sources in iTunes, when you eject the iPod shuffle the icon remains.

This allows you to fiddle with the playlist on the iPod shuffle without having to have it sticking in your Mac's USB
port. When the iPod shuffle is connected again it is updated to reflect the changes you made to the shadow copy.

I'm with Scott, this would be cool to have with all iPods, not just the shuffles.