I want to allow visitors to my site the opportunity to sign in or register from the sites home page. How would I do this?

The easies way which i used is to just create a hyperlink in your main page which has the same link as the login for the board and then you just implement a method which determines the calling page. My theme is matched between the site and the board so the integration is seamless. I then used YafBlend to get user info for the main page