Alvaro

hello David
I have installed wordpress 3.0.1 ,can you please guide me in which file i a have to add those 4 line of code as there is no mu-plugins folder

<?php
function ds_new_user_meta($blog_id, $user_id) {
add_user_to_blog($blog_id, $user_id, ‘author’ );
}
add_action( ‘wpmu_new_blog’, ‘ds_new_user_meta’, 10, 2 );
?>

i want all the default user have author role and they dont have any admin

yes you are correct,
i want my user to have a blog like blogger.com but in their blog they can create page and post and select theme and nothing else.
Everything else will be done by super admin like plugin available to them, etc

thank you andrea, I have got the option but i want only to register for site and not for user.In that option i am not been able to do so.the option which are given are
Registration is disabled.
User accounts may be registered.
Logged in users may register new sites.
Both sites and user accounts can be registered.

I need to have an option where user can register for a site and not for a username