I've read in the iPhone user's guide that when no wifi is available, the phone will use the cell provider's network to access the net. Does this really happen automatically, and if so, is there a way to turn this function off? I've got a friend asking me this - she tells me that her phone accesses online material when there's no wifi, and she doesn't want to pay her cell phone company for the access. At first I thought she just didn't see that there actually WAS a wifi where she was, but after taking a look in the manual, I'm not so sure anymore. Thanks in advance.