Setup a usergroup to create new categories?
 

I have an events album where I want a particular usergroup to be able to add new events. They will need to be able to title each new album/category for the particular event. It's not practiacal for me to create each category.

Can this be done?

Why not use Photopost user album feature and assign to cats. Create the parent category and set that particular usergroup as the only usergroup allowed to upload there besides you yourself.