I'd like to continue on the smartphone capability theme.
All the functionality I mentioned has caused lots of changes in society, but of course the smartphone wasn't the first device to cause them. The changes are foremost an IT phenomenon, but the smartphone takes them further. Why? Because of its versatility and superb mobility.
Consider the functions camera, camcorder, alarm clock, dictaphone, navigator, pedometer. These don't make sense on a laptop PC, but they are great to have on a smartphone. Others are well established on laptops, but to have them on a smartphone makes them even better: notepad, dictionary, newspaper, phone, games, radio, weatherman, post office, etc. Size is key to the smartphone concept and is also a key distinguisher generally in IT.
Size is also the key difference between the desktop PC, the laptop PC, the pad, and the smartphone. They are all general purpose computers, they can all do "anything", but they have different areas of application. You can use a laptop to navigate, but it's not optimal. You can write documents with a smartphone, but it's not optimal. None of the devices are going to kill off the other, becaue they all excel in some area. But what they all have done quite well is transform they way we do things.
The smartphone puts the power of IT into more hands. That enhances the networking effect of all things IT, which further speeds up IT development.