Do you need to rotate it for each user, or if one user views it and then another user views it, do you want it to rotate as well? If the latter, you'll need a server-side script. Otherwise, it should be doable with cookies and document.write().
You didn't answer my question. Is it okay if two different people visiting your site one after another see the same thing as long as the same person visiting your site multiple times will see the rotating content?
You'll need to look into a server-side script to do this sort of thing.