This Magento extension has the following goals:

X-Provide easy access to Facebook PHP SDK methods through Magento Model
X-Integrate Facebook JS SDK with Asynchronous loader
X--lazy loading of all XFBML tags, no need for iframe tags
X-Provide Facebook Login with Progressive Enhancement
X--Have the Login and Logout links with without the JS SDK
--Layer over the JS SDK login/logout for performance
-Option to auto-login users if they have active Facebook sessions
-Provide site Registration via Facebook
X--on click registration/signup
--have backend option for one-click registration?
--Email randomly generated backup password?? No...
-support for checkout registration?
-Make it easy to disable all Facebook features if Facebook goes down
X-Provide Open Graph tags for
X--Products
X--Categories
X--CMS/regular site pages
X-Insights for Websites header tags (added the fb:app_id OG tab)
-Provide Facebook Social Plugins:
--Like Button
--Send Button
--Comments
X-App Permissions/Scope support
-Support for extra user registration form fields in Enterprise?
-Support for Facebook Registration plugin?
-Support for Facebook scraper exceptions for private sales sites?
-Localization / internationalization
--populate a list of all of the supported Facebook locales
--auto-load the right locale based on the Magneto locale

-Can enable just some of the features? Leave comments but turn off registration?
-Respect global site registration and login settings (for private sales?)
-Deal with the new "persistent" extension in 1.6, which might make it tougher to override the login form


User Guide:

How to Setup
-install extension
--install all of the files
---including the channel.html and channel-secure.html files in the root
---
-create facebook app
-add facebook app Id to Magento backend
-how to get Facebook Insights set up for your website
-how to get the Facebook avatar for use in your theme<

Tips:
-how to insert login and other FBJS plugin blocks in your site
-users who register with Facebook have a random password - you may need to reset this if they ever want to log in normally