When you unlock your iPhone to work on different networks it will be ok... But be aware that you unlock your phone properly. becasue what you can do is BRICK your phone, and that there is solved by a restore of your software... Unlocking your phone to work on different networks does not affect the itunes, apps, music.. The only way the apps, music, itunes will change is when you Jail break the iPhone. Jail breaking is a term that one uses to put non apple programs on the ipod/iphone. Remember that the ipod touch/iphone use the same firmwire and the same software.