Merry Christmas everyone! My wife got me a new iPhone 3G for Christmas with the stipulation that I give her my old unlocked 2G. She had a contract on the 3 network, and when we put her sim card into the unlocked iPhone it gave an error that said "invalid SIM". I searched a bit on Google and I found a site that says that 3 used a different type of sim card than O2. Does anyone know of any way to make this work? Thanks!