Is there some sort of free software filesystem where you basically automatically sync it with a silo somewhere remote? I've got a new clean hosted instance, and

Is there some sort of free software filesystem where you basically automatically sync it with a silo somewhere remote? I've got a new clean hosted instance, and was thinking it would be neat to be able to use mercurial for source control on my laptop, and know that it was constantly duplicated on my leased hosting. Any advice?