Voluntary customer sign up without sale

We have many who come to the site and want to register as a customer even though they are not making a purchase on this visit.
Zen-Cart gives everyone the opportunity to sign up when they are making a purchase. It also has several locations where they can "unsubscribe" to the newsletter.

What we need is to know:

1. Are the newsletter and the customer databases one and the same?
2. Is there a way to provide a link to those that want to register without a purchase?
3. Are these settings someplace in the admin section, or do we need to add/change code?

Thanks to all who help. We've tried a whole lot of things. Don't know if we have exhausted all possibilities, but it feels like it.
:wacko:
ALG

The stock template has a Login link next to the Home link at the very top of the page. Your template may have moved that or eliminated it. The login page has sections for returning customer login and new customer registration. You can change the text of the link if you want to make this clearer. Search in admin > Tools > Developers Toolkit for Login; among the results will be the file and line number where this isdefined. Then go download and edit that file and upload it to your custom template folder.

There is only one database.

Thank you. I have found it, put it into action, and all is right with the world (again).

I apologize for not getting back here sooner. Up to my neck in aligators, and someone sharpened their teeth! :-|