posted by JustDave:
Authentication with an empty string should be all that is needed unless your after more than the basic information of a user.
This code:
$userob = new user;
$user = $userob -> authenticate("");
Will return Username, Password, SessionID, StyleSheet, Status, # New Privates and Front Page prefs.
If you need other information you can add as needed to the authentication call. 
Thanks! The problem is that I'm not automaticly logged in when I hit the page. I can tell I'm not logged in cause I don't have "Admin" in the menu. How can I get a registered user to automaticly authenticate to the index page?