Hi,
I have a category structure like this in WordPress (that is echoed with wp _ list _ categories):
Works
    Photos
        1990-2000
            Photo #1
            Photo #2
            Photo #3
        2000-2010
            Photo #1
            Photo #2
            Photo #3
    Paintings
        Watercolor
            Painting #1
            Painting #2
        Oil paint
            Painting #1
            Painting #2
I want to highlight all parent categories while browsing the category child. For example: when I am on Works->Photos->1990-2000, I want all of the categories that I've gone through to appear bold.
I use the show active category plugin ( http://www.screenshine.net/blog/1474%5Fwordpress-plugin-show-active-category ) to achive this when I am browsing a single post.
The paramenter current _ category ( http://codex.wordpress.org/Template_Tags/wp_list_categories#Parameters ) is something that I think can be usefull...
Thanks!