This is all done because of the record labels. Think about it. If you could sync an iPod to a machine going from ipod to computer, anyone with a full ipod could transfer songs to anyone they wanted to. Think of this as the way Palm software works. With Palm you can choose whice device overwrites the other, in essence, this is not "syncing" the information. Technically the ipod synced with the itunes playlist. If you were to have an ipod full of music, say for instance you dumper you itune library to the ipod because you were reformatting your hard drive, you would not be able to get the music back into itunes with out using something like ollies ipod extractor.