Back in the 1970's IBM had the idea of the mainframe. The idea was that everything was stored on central computer and people used machines - ie computers that looked more like just the screen and a keyboard - to access it.
That idea kinda went away went Bill Gates focused on the personal computer.
Now, the internet is here. Now, the cost of memory and computing power is going down. Now, the cost of internet access is going down. So it feels to me that the age of the mainframe is coming back - the difference being that it is not one company on the services/mainframe side... It is hundreds of thousands.
The point of this post is that a lot of things that used to be "on the computer" are now being hosted elsewhere - and you just access them via the internet. The industry calls is ASP's - Application Service Providers.
This is exactly what Drop Box are doing. They are providing the virtual service that can replace what used to be on the computer.
So very soon, perhaps we will have computers that just have screens and keyboards - and nothing actually stored on the computer - music, photos, files etc will all be stored elsewhere and you use the internet to access them.