There was something like this for years called Symform but they shut down recently: http://www.backupreview.com/symform-to-discontinue-peer-to-peer-cloud-storag

There was something like this for years called Symform but they shut down recently: http://www.backupreview.com/symform-to-discontinue-peer-to-peer-cloud-storage-service/ http://www.backupreview.com/symform-to-discontinue-peer-to-p... I guess this was more of a commercial solution though.