I see that I can order the iPhone 4S from the Apple Online Store. They say they will ship it to my house for free. So how does the activation work - is it already activated when it arrives at my house? But what about my current iPhone 3G - I want to still be able to use my iPhone 3G before the 4S arrives. If they activate the 4S and transfer my current phone number to it, then won't my 3G stop working?