Hello,
Following this quick tutorial, I was able to successfully hook into the category write panels with the following:
add_action('add_category_form', 'my_function_blahblah');
add_action('edit_category_form', 'my_function_blahblah');
add_action('create_category','my_function_blahblah');
add_action('edit_category','my_function_blahblah');
Now I'm trying to figure out if I can do the same thing for a custom taxonomy? Is it possible? Any clues? :-)