Recently upgraded to the 5 and want to use the 4 as an iPod to access the internet listen to podcasts. I see that I am no longer able to make calls from the 4, but it still says "Verizon" up in the left top corner. I was directed to this through searching, but the Verizon 4 does not have a sim. http://support.apple.com/kb/HT3406 Do I need to do a reset and restore to it? Or should I just leave it...or maybe even just put it on airplane mode w/ wifi?