This is a pictorial history of the evolution of the phone which comes with this article, Evolution of the phone: From the first call to the next frontier.

The phone is my favourite example of a technology that never stops changing. And if we were to go back and think in terms of communications, the pony express existed for about two years and was almost immediately replaced by the telegraph. And all of it has been entrepreneurially driven, with governments only becoming involved because for the longest time, the phone was a natural monopoly where competition was constrained by the capital requirements. Still somewhat true, but nothing like it was, which is why the private sector has been finally able to muscle governments out of the way.