is there a way to make all urls **
 

i know you can selectively make certain words *****, but is there a way you can make ANY url ****?

yes ;)

can you please tell me how to do this?

Let me see if I understand this correctly.

Example: http://www.vbulletin.org

Will be replaced with a bunch of stars. Right?

You can do this in admin/functions.php

You can add a preg_replace to replace the URL with stars inside the function censortext()... ;)

Alternativly you could had the URLs you want banned to the list of censored words.