I am very interested in how to set this up. I looked in the unison manual a while ago while I checked out dropbox. It didn't mention about this capability...
Unison can very quickly and easily replace DropBox for non-sharing use-cases
Posted Sep 19, 2010 20:01 UTC (Sun) by kreutzm (guest, #4700)
[Link]
Just search for "backup" in the manual of unison.
I haven't used that feature myself, but otherwise I'm a happy unison user (for a brief time even under windows) and except for the speed sometimes I wouldn't know why I would need any other (external) service.