The iPhone...... Are you kidding me.... Would be curious to know the age range of the survey takers if possible.

I would agree, Language, use of Tools, Electricity. All of which combined ALLOWED for the lightbulb. Some on here while great, have more, basic beginnings. Others are so intertwined that they could be combined into a common object. While yet others are debatable with other great things. Joseph Lister would be up there with his advancements in the medical community, whereas Penecillin's overuse has potentially helped to create "superbugs" which are immune to some anti-biotics, etc.

But the iPhone.