Another from my wish list: combo of related posts & breadcrumbs

I'd like a breadcrumbs plugin that gives me an option of also showing related posts or posts from the same category.

At the top of the page, breadcrumbs would look like this:
Home > Category > Subcategory > Current Page

At the bottom of the page, it would be cool to give readers the option of opening up category or subcategory, like a sideways file tree.