I second the recommendation of Crashplan. Setting it up so my parents can remotely backup to an external drive connected to my machine (to which my own backups

I second the recommendation of Crashplan. Setting it up so my parents can remotely backup to an external drive connected to my machine (to which my own backups of course also go) was a breeze. Ironically, I regularly switch that drive with the offsite backup that I store... at my parents :).