I recently had a rougue post on my board, it was by a new signed up user - who made 1 post only!
in this case it wasnt sooo bad, as they were just having a joke, but it would of been nice if I could of searched for every post by IP address rather than the 'last 10 posts' option. This 'MAY' of told me the culprit straight away.
I did try a query in phpmyadmin, but it kept returning all rows! lol - I guess I should get a book on mysql
Anyway, a mod like this would be a good addition to the admins toolkit.