Sorry about that...I forgot how I coded the popup between the time I wrote it and the time I made the comment about using it as a popup.
Here's a complete solution, including control over the popup characteristics:
You could use
var urls = ["http://www.espn.com","http://www.disney.com","http://www.codingforums.com"];
var rotate = 0;
function goRandom( )
var newwin = window.open(
urls[ rotate ],
"height=400,width=600,scrollbars=yes" /* add options as desired */
rotate = ( rotate + 1 ) % urls.length;
<a onclick="return goRandom();">click here</a>
to get rid of the separate increment of rotate, as Adios did. I just find it clearer to write as I did.
urls[ rotate++ % urls.length ],