Good evening, I have AT&T and a iPhone 4S. I just came back on business travel from Norway and found something very interesting. Over there you can have a twin sim card meaning you can have two phones, one for business and one for personal use. When someone calls your number it will ring at both, even better, when someone texts you it also goes to both devices. Has anyne heard of this before here in the US? If so how can I get that to work here?