I just found an interessting blog post about Time Machine backups to a FreeBSD server.
I haven't tried it myself but the idea seems nice. Automated Time Machine backups to a network mounted FreeBSD server over AFP (nettalk).
Seems like a good way to deal with personal backups on OS X clients. Rigth now I just hook up an external drive but automated backups to a ZFS FreeBSD server with the Time Machine magic seems like a great solution.
The original blog post with instructions http://blog.khubla.com/freebsd/timemachine-backups-on-freebsd-10