To improve my backups and utilisation of my Raspberry Pi's, I've added Bittorrent Sync to my XBMC Pi. It's running RASPBMC on an original 256mb pi.
I'll need to see if it affects the performance of XBMC once the initial data sync has completed.
Basically I followed the instructions I made previously, but had to do a couple extra things
manually add a .sync folder
sudo mkdir /home/pi/.sync
sudo chmod 777 /home/pi/.sync
edit the config
sudo nano btsync.conf
change this line to this
"storage_path" : "/home/pi/.sync",
To get the killall command to run I had to install it using this command
apt-get install psmisc