Assume that you visit your friend someday and find that hes having some great music on his iTunes that you have been wanting to keep. So you want to copy some of the music on his iTunes to your iPod without losing you own music on your iPod. What should you do? You have to transfer some of his music from his iTunes to your iPod. But if you do so, all your own music may be erased and what all your iPod keeps is his music after syncing your iPod to his iTunes. So the first step, I think, you should transfer your own music from iPod to his iTunes. However users can sync iPod to iTunes easily but the opposite direction from iPod to iTunes is not possible unless you use a third party program. With this nifty Aniosoft iBackup, it is not difficult to move content from your own iPod to his iTunes with no any change and risk including its original arrangement such as playlists, ratings, play count and etc. After transferring content from your iPod to his iTunes when his iTunes having both your iPods content and his content, it is time for you to sync your iPod to the iTunes. Finally your iPod just get all his music without deleting your own music. If you just want to keep some of his music (not all of them), just plug your iPod to your exsting iTunes on your PC, transfer your iPod with all these new content (meaning adding some new music from your friend)to your existing iTunes on your own PC with Aniosoft iBackup once more ,deleting the songs which you dont want to keep in iTunes and finally sync your iPod to the iTunes. Another similiar case :when you get a new computer or laptop ,install a new iTunes,you want to add more songs on your iPod without deleting its original songs on it.