Ad Rotator

I am in need of ad rotating software for my websites. I use a combination of ad networks (such as google adsense, cubics, etc,) and I need some software so that I can: 1) Rotate the advertisments in different locations on different pages. ie: Visitor 1 sees an adsense ad on the top of the page while visitor 2 sees an adsense ad on the bottom of the page, etc. 2) Rotate different advertisments: ie: Visitor 1 sees an adsense ad while visitor 2 sees a cubics ad. 3) Stat tracking which shows how many impressions each set of ad code (adsense, cubics, etc.) has shown, the click through rates of the different ad codes. That's it