http://ezine.daemonnews.org/200603/dermouse.html
This is an interesting way of dealing with backups. It might be interesting to see it ported to OpenBSD, although it would have to be desired by many for it to actually be accepted.
I’m not sure how desirable it would really be. Would people really want to either (a) completely fill up their networks with backup data or (b) have to add another knob to a system that is philosophically opposed to adding knobs whenever possible?