The HowTo Forge website has this new tutorial posted today taking an extensive look (complete with tons of screenshots and code along the way) on how to create a Facebook RSS reader to add to your blog of choice.
This guide shows how you can build an RSS feed reader application for the social network Facebook that will display your blog's/web site's RSS feed on the profile pages of Facebook users (that have installed the RSS feed reader application). Each item of the RSS feed will have a Share button so that people can share the story with their friends, and the application will have an Invite link so that people can invite up to ten friends at once to also install this feed reader application.
They use PHP5's functionality to make building the reader simple and take advantage of Facebook's simple application system to make the reader. You can stop after the first few steps of the tutorial and have a working application, but they take it further. They show how to make customizations to the reader, making the feed auto-update, creating an icon for the app and make an invite page.