It seems that no device in history has revolutionized societys ability to communicate more than the telephone. The apparatus invented by Alexander Graham Bell has gone through numerous iterations to become the modern device known as a SmartPhone, which is capable of performing many functions in addition to speech passage. But at the core of any cell phone or even SmartPhone, the primary function is to allow speech between people in distant locations. Human history would have turned out quite differently than it has if such a device had been available over the last 2,000 years.
The outcomes of wars might well have been different if nations had had access to instantaneous communication. Some wars might even have been prevented if countries who unified into opposition forces had been able to communicate between themselves, and thus present a unified cease and desist command to the aggressor country. As a young nation, fighting for its freedom from British rule, America sent one of its best and brightest to France to negotiate their allegiance, in the form of Ben Franklin.
A natural leader and politician, Bens years in France, spent away from his beloved wife and the new country which he by then called home, could have been spent far more productively in America, had he had access to a telephone. This device in hand, he could easily have reached the influential politicians which he needed to forge alliances with, and could perhaps have sped up the conclusion of the American War for Independence.
Instead, he was relegated to prehistoric communications means in the form of face to face speech, or even slower methods in the form of letters carried by horseback, then on a boat across an ocean. The War for Independence dragged on for years, partially because it took so long to arrange even the simplest of tasks or alliances. Not only individual lives, but many nations worth of entire populaces, were affected for a long time because communication methods were not available which are completely commonplace today. Remember to appreciate the time that a telephone saves you each day!