That'd be a really tough choice for me to argue with. About 150 years the camera has been around and the changes are just profound.
It has not changed History so much as it has changed the way we SEE history. Matthew Brady's battlefield dead in the Civil War for example. And it seems that everybody alive today has been permanently recorded on a camera...
Yeah I don't think it's changed history per se but it has certainly changed the way we think of things. Some of the most iconic photographs like the raising of the flag at Iwo Jima (spelling?), the march on Washington for Civil Rights and so many others all captured and etched in the brains of millions. I think I might have seen the Civil War picture but I will check to make sure I am thinking of the right one!