A friend of mine has both on her desk and mixed up the cables. Both iDevice's (iPhone 4, iPad) USB connector plugs (the large ones) look identically. (The old iPhone 3G's small USB plug is a bit rounder by the way.) She realized that iPhone 4 is connected with iPad charger after some seconds—iPhone's behavior was normal as if connected with the correct charger—and disconnected immediately. Then she connected iPhone with it's original charger and still normal behavior. So it seems that it was not harmful for the phone. Since the iPad's charger has more power the question is: Can my friend connect the iPhone 4 (and maybe the old iPhone 3G) with the "wrong" charger without hesitation as often and as long as she wants? Could it be harmful to the charger? What do you think? Maybe I'll call Apple Support but I don't want to give them any hint that it could have happened to me… uhm …my friend, in any case of guarantee. Thanks for reading and thanks for any hints in advance.