Check this cool script “AJAX banner rotation” , Sort of Ajax version of phpadsnew but the simpler side, lol.
Have look at the demo you’ll know what I mean.

So here’s the case: rotate ads on a website, even when the page is not reloaded. If the chances are that the visitor will spend more time on a page, it makes sense to opt-in for displaying more than one ad at one page load. I’ve done this in the past using iframes, but hey, it’s 21st century (the last time I checked) and we have AJAX!

Author, Stoyan have has made something similar to the Million Dolloar Homepage with ajax here at The Invisible Ad theInvisibleAd.com