Update as of 2023: This add-on is now depreciated
Facepaste is a Firefox add-on that makes it simple to downloads entire albums from Facebook.
The advantage of using this add-on is that no third party can access your Facebook account on your behalf unlike many stand alone Facebook album downloaders.
Install Facepaste from here .
After installing, to download any Facebook album, just select a picture from it and right click. Then select Download this Facebook album and choose an appropriate path for storing the album images.
The popup window for this will display the number of images present in the specific album and their download progress.
The popup will finally change to complete once the entire album is downloaded.