hey guys so i'm not eligible for an upgrade yet but i would like to purchase the iphone4. so this is my plan, my mom is on a pay as you go plan at the moment. i would like to have her get a new iphone 4 and then trade phones with me. so i'll give her my iphone 3g since she is only going to be using it for phone calls and i'll take her iphone4. only problem i see is that the iphone 4 has a micro sim and the 3g does not. i read on some forum that using a sim other then the one that was provided for the iphone4 will not have all of the features on it. the 2 sims look pretty identical to me just smaller. are sims able to store features on it? i would also like to keep my phone number and my unlimited data plan. what do i need to do?