search for: category_item

I was wondering if anyone knew of a way to combine the new nested forms in rails 2.3 with a has_many through relationship via checkboxes. Basically I have a page model, a page_category model and a category_items join table. Pages have many page categories through category items. The category_items table is polymorphic so i can use it for other models who need categories (maybe this is overcomplicating everything though?). In a page''s edit form I want to be able to dynamically add new category...