My idea is to use iTunes with the iPod to be able to organize the music and play it on both the iPod and the computer, but to also be able to not sync it. Essentially the iPod would be used as a music hard drive that employs the use of firmware to make it possible to play music on it. To put new music on, one would transfer it from the computer to the iPod. To play music from the iPod on the computer, one would use iTunes to "read" the songs and their tags. When the iPod would be ejected, the songs could not be played on the computer.
What is perhaps the main point to all this is to free up hard disk space on the computer. However, it could make it possible to use iTunes as essentially an organizer and reader for really all mp3 players.
Sorry if this has been said before.