BuddyPress.org

This plugin works and looks to have the bones in place for lots of successful customizing.

http://www.justin-klein.com/projects/wp-fb-autoconnect

It comes with a sidebar widget, but with @justin_k helping, I put it directly in the sidebar:

<p></p>

<?php

if( wp_get_current_user()->ID == 0 )

{

if( function_exists(‘jfb_output_facebook_btn’) )

{

jfb_output_facebook_btn();

jfb_output_facebook_init();

jfb_output_facebook_callback();

}

}

?>

in sidebar.php

check it out at http://housingstorm.com