I'm not big fan of using Facebook login. I would think that it raises a barrier of entry for users, either because they don't have a facebook account or because they don't know what side affects your app will have. You don't explain what the advantages of using Facebook, or what integration there is with facebook. How will it affect the users's facebook account. You said in your post that it does not post to your wall, but you don't say that on the site that I can see.

Also the footer links are not links. You can't click on them. If I just say this page, I would not sign up because it doesn't look real yet with just a single page.