Having browsed at 0 and seeing many items far more influential noted - I'd note that most of the items proposed hardly qualify as a gadget.
Aside from prototype nuclear weapons, I can't see a circumstance where I'd accept 'gadget' as a descriptive of an item which couldn't be held in the hand... "Hand me that gadget over there", pointing in the direction of a hair dryer / cell phone / power drill / etc, sounds reasonable to me, while "Haul that gadget over here", pointing at a chain engine hoist / deep freezer / electron microscope / etc, sounds bloody odd / incorrect.
None of this is to say that I agree with the iphone as a choice... I don't. I just don't think an airplane or printing press qualifies as a 'gadget'... A gun, however, might.