I am not sure how complex this would be
but in version 2.0 you could add 2 sponsor hacks which one was the category sponsor hack and the other was the actual forum sponsor hack
Now to make more of a request maybe we can make it in a way where phppads or some other freeware type of banner control system can be used.
we use both examples at
http://www.srtforums.com
I would just like it for 3.0