I think the biggest OSes _have_ integrated something like this, but unfortunately they don't work well between operating systems. So if I'm on an Android phone,

I think the biggest OSes _have_ integrated something like this, but unfortunately they don't work well between operating systems. So if I'm on an Android phone, an iPad, and dual boot Windows and Ubuntu then it doesn't really help. Dropbox does allow me to backup and sync on all of those.