views filter

I'm well aware of Views Or; I'm looking for something that would do a Conditional Filter. Example:

I have a CCK field called showcase. If there is any node with the showcase field set to TRUE then I only want to display nodes of that type. But if none of my nodes have showcase selected then I would like to ignore this filter to still display nodes in this view. View has a random sort; also using sorting to do filtering doesn't seem like the correct way to do this.

Has anyone created a views plug-in like this?

Hello,
I'll start with the good ol' i'm new to drupal and creating custom modules spiel...
(btw, im using the most current versions of drupal and views)
What i need/have been trying to do is create a filter for a view that uses select dropdowns based on values that are collected from a cck text field.
(for example: a user adds a new node, there is a field called type and the user can enter whatever he wants. when the form is submitted, and he goes back to the list view, his entry in the type field now shows up in a select dropdown along with all of the other options that other users added. now he can filter the view with his own type entry.)

Help! I know this isn't the right place to post this, but I'm not getting help from the OG list and I'm getting desperate - school started yesterday. I upgraded my site, well actually recreated my site on Drupal 6. Last year, I had several blocks on each group home page that would display information pertinent to that group, for instance FAQ's or upcoming class birthdays. I did this easily with the views filter, using "OG Posts in Current Group" and "OG Posts in User-Subbed Group", making sure that it was on the right page (view) and the user was allowed to see it.