Able to change Categories only

I was wondering how I could create a user that only had the ability to change the categories of every story, and nothing else. I am using WordPress 2.0, and I would like to work on recategorizing stories, but I need help to do it.

I would ideally like to hire someone to help me with categorizing the 600 entries, but I don’t want them able to do anything other than changing the categories on stories.

Possible?