Has anyone else tried using a 3G SIM card in an iPad 4? I have taken the 3G SIM card that I usually swap between my iPad 1 and 2, and plugged it into my iPad 4. It seems to work, but I just got around to trying it in an area with a so-so signal. I alternate between getting about three bars and Edge service. I will have to test further when I get a chance. If I find that it works, I'll keep using 3G on all three iPads interchangeably, even though iPad 4 supports 4G. That's because I'd rather keep the flexibility of swapping iPads on the go, when one iPad or another is low on juice. In that case, I just pull the SIM card and use it in another iPad. Is anyone else doing this with any success? I've been doing it on iPad 1 and 2 for more than a year, with AT&T's knowledge, but they're both 3G devices.