The thing is, with my iPod, when the battery is fully charged, the screen shows the battery cell icon full and says "charged." As far as I can tell so far, the iPhone doesn't have any text with the battery cell icon to state that the battery is fully charged, so I don't know when it is, or if the graphics just make the battery cell icon full when, in fact, the battery capacity is just >95% charged, or whatever.
But maybe Apple omitted all this info and feedback because it doesn't matter, and we are just being overly concerned.
-CJ