Git-annex does encrypt if you set the other site(s) as a special remote - a good way to use it with less technical friends is to get a Windows rsync server (there are some with simple GUIs for start/stop) and set that machine as an encrypted rsync remote.

http://git-annex.branchable.com/special_remotes/rsync/

I had not seen that before, that's perfect. I had been looking for something like that but some time ago when I had looked it wasn't so easy to do.