For those that wanted a pre-made leaderboard, here is one I made:
http://s000.tinyupload.com/index.php?file_id=72443483567597873242
The leaderboard shows 10 players at a time. You can go to next / prev 10 players. There's also a button to view the top 10 players, and button to view your position in the leaderboard.
It shows Player rank, score, name, and image.
I can't give much support, but feel free to use it.
To test it, just change the name of the leaderboard (mine is non-contextual), and upload the export to facebook, all submitted scores will show up. (note: I've only tested with a few players in the leaderboard)