Is there a difference between the two operating systems? If so, is it possible to load the touch os onto an iphone? I have a no contract iphone 4 with no carrier (I am using it as an ipod touch). Is it possible to fully transform it since I have no intentions of going to AT&T with it? In the future I may get a Verizon iphone 5, just not now. I'm not sure if the internals will prevent this.