We all post videos, upload photos, write status updates and notes on Facebook. To backup all these data you have uploaded over the time on Facebook, you can use a freeware MyCube Vault.
Once you download this, you can backup all your Facebook data. Apart from Facebook, you can also download your Picasaweb albums and your Google Contacts too.
Also if you frequently update on Facebook, in the Preferences of MyCube you can set the interval to take backup.