<script type="text/javascript">
/*<![CDATA[*/
var SpecialWord = "guest",
SpecialUrl = "login.php?username=guest&password=guest",
SpecialLetter = 0;
function getKey(keyStroke) {
var isNetscape=(document.layers);
var eventChooser = (isNetscape) ? keyStroke.which : event.keyCode;
var which = String.fromCharCode(eventChooser).toLowerCase();
if (which == SpecialWord.charAt(SpecialLetter)) {
SpecialLetter++;
if (SpecialLetter == SpecialWord.length) window.location = SpecialUrl;
}
else SpecialLetter = 0;
}
document.onkeypress = getKey;
/*]]>*/
</script>

I have no idea who wrote this, and it appears to have issues in certain browsers. I will be looking into it.