Hello. I move around different countries (from a few days visit to long term stay) often. I am considering to buy an iPhone 4S. Could you please let me know the following: 1. Is buying/using different SIM cards in different countries the recommended way? 2. As far as I know, each SIM card comes with a different phone number. Is there a way to use the same phone number all the time while in different countries? Will doing so cost more money? It would be difficult to inform everybody that I change the phone number whenever I visit a new country. 3. As least locally, each SIM card can be used for a few months. If I do not add money to the current card before the expiration date, I will need to buy a new card with a new phone number. This may apply to several countries. In other words, unless I keep adding money before each expiration date, I have to change my phone number in different countries every few months. That will be expensive and too complicated. How does this work? Is there a recommended way to solve this issue? 4. There are rumors that the iPhone 5 will be out in October. As far as I know, the current iPhone 4S is 3G only. Is it fast enough for browsing even complicated websites? 5. Do you expect many big countries will use 4G within a year? Thanks.