Here is a little test script I just wrote and should work to cloak links client-side, i wanted to share with you guys, specially newbies
This shows a normal link (internal link) to the user when hovering, but when he clicks it takes them to other link (internal or external, aff. link for example)
Note: I haven't tested it very much, but should work in all major browsers

Note also: you should also cloak server-side since google Will see this and f*** you
Code:
<html>
<head><title>Cloak test</title>
<script type="text/javascript">
var CLOAKED_LINK = "your-evil-script.html"; //change this value to your link
function cloakIt(event) {
event.returnValue = false;
if(event.preventDefault) event.preventDefault();
window.location.href = CLOAKED_LINK;
return false;
}
</script>
</head>
<body>
<a href="./friendly.html" onclick="cloakIt(event)" >Soccer</a>
</body>
</html>