Since a number of other people have already mentioned Dropbox, I'l mention something slightly different: git-annex (http://git-annex.branchable.com/ http://git-

Since a number of other people have already mentioned Dropbox, I'l mention something slightly different: git-annex (http://git-annex.branchable.com/ http://git-annex.branchable.com/) It's a more general piece of software, but combined with git-annex assistant and your choice of hosting provider(s), it lets you create your own cloud storage, so you have potentially no concerns over privacy[0]. If you're looking for fault-tolerance, git-annex lets you distribute this storage over an arbitrary number of providers easily, so you can get redundancy between an array of cloud hosting providers. I've been using git-annex for several months now, and while it's still a work in progress, I haven't had any issues at all with it. It seems to be very reliable and bug-free; the main things being developed now are additional advanced features and an improved GUI interface, etc. For people already accustomed to using git on the command line, though, it should be a seamless experience. [0] This depends on how much you trust Amazon/Rackspace/your colo/etc., but that's a separate level of trust altogether.