How high are we allowed to fly? I think I recall hearing 400 feet per FAA rules... is that right? Also, if I'm flying this from the top of a 200 foot hill... I believe the iPhone app will show that as "0" altitude, right? Or is it supposed to show the actual altitude above sea level? I can't recall, but I'm pretty sure the app was showing me how hi the Phantom was above ME (not sea level)... in which case, what is the FAA rule? thx.