Custom Fields for Categories

Hi,

When we add a category, we have the following fields:

Category Name
URL Name
Parent Category
Description

The question is, how can I add custom fields to it and how can i display them in the single post showing the category(es) custom values this post belongs to.

Is there any plugin out there that do this job ? What if a post belongs to more than 1 category. The function get_the_gategory_field(‘<custom_field>’) will return an array of pair ‘field_key’=>’field_value’

Hoping a quick answer, Regards, Ed