WordPress MU

I am planning to make a limited number of blogs, maybe 20, using WP-mu. The idea is to give those 20 people a blog each /server/wpmu/blogxxxx/, with an user+pass.

(I cannot have a smpt, mail-server)

I don't want readers to be able to get a blog filling the email form. Just this email form to disappear.

New blogs could be made vía admin-user.

Hope I explaint myself. Any hints??

Been discussed before. Best bet would be to rename the wp-signup.php file (You may deside to use it later on so you probably don't want to delete it) and don't offer any links to it or, if you're lucky and they all have the same domain for their email addresses, limit registrations just to that email domain.