A few weeks ago I damaged my iPhone4 and started using my original iPhone until the 5 is released. Of course the only internet access is via the EDGE network. Not to shabby really and I figured it'll get me by for awhile. I downloaded PDANet from Cydia and have been tethering my iPad via my iPhone. I have yet to receive any notification and now wonder, after having done this for a few weeks, if it is possible AT&T is only monitoring 3G usage and not the EDGE network usage when it comes to sending out tethering notices? If so, this may be something to consider and even those with better and newer iPhones can always shut 3G off and use EDGE exclusively while tethering. It's a bit slower, to be sure, but not really as bad as you would think when it comes to casual net surfing. Of course my "evidence" is anecdotal, at best as I'd like to read others having the same experience before confirming this works.