I want people to be able to comment regardless of being registered or not (by providing email etc.)

Go to Settings >> Discussion and tick the following two boxes:

• Allow people to post comments on new articles
• Comment author must fill out name and email

Be sure to use a spam filtering plugin with this option! Akismet works well and is free; I find that WP-SpamShield works even better.

I want to provide additional functionality for those would ‘do’ choose to register.

Go to Settings >> General, and tick the “Anyone can register” can register box. In the “New User Default Role” select the default role for self-registered users.

A complete list of roles and capabilities can be found here. If one of those roles doesn’t work for you, you can use a plugin like User Role Editor to create your own.

All the plugins I mentioned are either free and or have free versions that will do what you want.

I’ve now installed WP-SpamShield so all of what you mentioned above is accomplished. How do I get the registration / login piece to show up?

thanks again!
Kip…

that hasn’t displayed any registration pop up or screen for the use to actually register themselves

You would need to provide a link to the registration page—this isn’t the sort of thing WordPress does natively.

There are free plugins that you can use to generate a pop-up window, however.

Thanks,
Kip

Blessings,
Kip!