WARNING: THIS THING IS OBSOLETE - DON'T USE IT
Use this one instead: django_facebook_oauth
This app extends the built-in Django auth system to let your visitors use their Facebook account to log into your site. It works with existing user accounts and django-registration (although django-registration isn't required). Your visitors can still use their Django username and password, or they can log in with their facebook account and link it to their existing Django user account. If they don't have an existing user account, they can log in with Facebook and a dummy Django user will get setup for them seamlessly.
This stuff is all a work in progress so its rough around the edges. I try to keep trunk working, but there might be API and behavior changes if you try to keep up to date.
I would love help on this project - testing, bug fixes and project planning. There are not a lot of features that need to be added, but it still needs work. Contact ryan AT bariserver DOT com.
You can grab a zip of the code on the downloads page.
Michael Trosen from Lab305 put up a nice presentation with some instructions on how to integrate django-facebookconnect.