I bought an iP4 and gave my old 3g to my son. He was using a razr before. I took them sim out of the razr and put it in the 3g. He has been downloading apps, surfing the net and making calls just fine. I am not being charged for any data use. Now, true that much of the time he is using wifi, there is enough 3g usage that I thought some charges would have appeared, but none have. Obviously, I do not plan on questioning this too much, but I am curious if there are others using an iPhone without a data plan.