Facebook is one of the most popular photo hosts on the Web, but when it comes time to get your shots off the service it's also one of the worst at providing tools to do the job.
A solution called simply "Get my tagged pics" does the heavy lifting for at least some of your shots, or rather shots of you. Any pictures that are tagged with your name gets grouped together into sets of 10, which you can pull down to your hard drive as a zip file.
The system is not entirely perfect. For instance, if you're looking to archive the 300 or more shots of yourself that have been accumulating over the past several years this is a tedious system. Also, the shots the application grabs are full size for Facebook, but not the original quality of the shot. Facebook squishes them down for the sake of page load and storage, and as a result you can't enjoy some of the full-quality goodness of the original copy. Still, it's better than going through your photos and saving them one-at-a-time.
Having had a lack of similar options on photo host Flickr, and with no official support for FTP backup, many developers have created archival tools that leverage the service's API. The same ecosystem has been noticeably absent from Facebook, which in the case of an eventual move to another service, could mean leaving your photos behind.