On my site I have 4 spots that randomly rotate the text ads. All I did was create a campaign for each advertiser and linked the banner to the 4 zones. Each advertiser has only 1 ad in their campaign, but should work with any number of banners in the campaign.
There is also a setting for the campaign I think that says don't display more than 1 creative for the campaign on the page. This stops it appearing in more than one zone on the page.
End result is the ads rotate randomly across all 4 zones and never repeat on the page in the same page impression.
Sure did. I just added the code intended for the head of the page into a text box placed in the top of the left column. The code for the ads is then included in the right column. Seems to work fine. Not that I am selling a lot of ads but that is another matter.
You may want to consider openx.com. They have a free hosted solution that I also use and so far I think it is better for serving ads.
You can see it in action on beadershsowcase.com. In the right column the section titled Member Announcements are all served from openx.