I will be living outside of the U.S. for one year (in Dublin, specifically). The most confounding part of the trip is trying to find a practical and simple way to use my mobile phone for data services, such that I will be able to "pick up where I left off" when I return home for holidays and at the end of my stay. The criteria I'd like to satisfy are as follows: 1. Once unlocked, I'd like to continue to use my iPhone with an Irish carrier. Seems simple enough. Unlock the phone with my current carrier (pay the fee), and pop in a new SIM from an Irish carrier. 2. Keep my current U.S. number "alive" so that I can return to it when I'm back in the U.S. This also seems easy enough; I can suspend the number and pay a nominal monthly fee to keep the number in my possession while inactive. and finally... 3. I'd like to seamlessly communicate with the contacts I already have. This is impossible with non-iOS users; I'll have to give them a new phone number. But what about iMessage users? If I use my iPhone with the Irish SIM, will iMessage users still receive messages from my name in their contacts? Do I need to provide them with my email address for this to work, or will iMessage manage all of this via my Apple ID? All the best.