i have 2 iphone 4's. One of them works fine, but the second one does not have a SIM card, therefore i cannot activate it. Is it safe to remove the sim card from my first iphone and put it in my second one just until it's activated, then remove it and place it in the first one again? I don't need to be able to make calls or anything on the second one, i just want to be able to get to the springboard and use a wifi connection. Will this mess up either of the phones and/or the sim card in any way? I am giving it as a gift today and don't have time to get another sim, and think it would be rude to give a phone that you cant even use.