VIA WIDGET FUNCTIONALITY:
What I'm wanting to is not show my newsletter subscription widget, if people are logged in.
Logically, then, I am wanting to show a widget only if users are not logged in.
VIA THEME SELECTION
If there is a plugin that automatically shows a particular theme to logged in subscribers, then I would just use the same theme twice, and add particular features for the subscriber theme.
I've found two theme switcher tools, but they basically look like they give people the option to switch themes. What I want is to manage what logged in and not logged in visitors see.
Does that make sense, and how could I do it?