Pogoplug is a service that allows u to map your drive everywhere, probably is slow, but for example. you can be with your notebook anywhere in the world and you can access your harddrive directly from the pogoplug drive.
the pogoplug cloud, is 5GB of free (you can purchase more if you want) cloud space. its like dropbox, so you can put files there.
what i do is to mirror my documents to that cloud, in that way im always sure that even if some day at home the electricity shuts off, im going to have access at least to the documents folder cuz those documents are in the cloud.
you can access them all from any computer, anywhere in the world, even from android or iphone.