If you want users to be able to create an account on your site you can use anonymous registration. Beware however that your site will not become an open messageboard to be used by spammers.

Enable Anonymous Registration

To turn on anonymous registration go to the Admin Console under Settings select the tab user. On that tab select yes at the radio button for anonymous registration.  When you hit save new users will be able to register themselves.

After you enable this feature, a new link will appear in the Login form to allow users to create an account. The url structure for this is <url>?op=auth;method=createAccount

Anonymous Registration Template

The template for anonymous registration is accessible through the admin console, under 'Settings' -> 'Authentication'. Information about the template variables are currently available in the WebGUI Online Help.